Errors in the log - Trying to access array offset on value of type bool

Steps to reproduce

1. Go to: settings - admin - logging

Expected behavior

There should be no errors for application.

Actual behavior

There are lot of errors from mail application.

Mail app version

3.5.0

Mailserver or service

few commercial free accounts from onet.pl

Operating system

Ubuntu 22.04.3 LTS

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database

MySQL

Additional info

I have few email account configured mostly for reading and deleting messages. No fancy use case.
I have observer that there are a lot of errors in nextcloud log.

{"reqId":"2huJjuwbcLlkjBdkj9Sb","level":3,"time":"December 23, 2023 16:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"VbvKFdtpPm3WrXPT6ayD","level":3,"time":"December 23, 2023 18:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"VbvKFdtpPm3WrXPT6ayD","level":3,"time":"December 23, 2023 18:00:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"VbvKFdtpPm3WrXPT6ayD","level":3,"time":"December 23, 2023 18:00:08","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"vZdUOEgS99WINXrCBydu","level":3,"time":"December 23, 2023 19:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"vZdUOEgS99WINXrCBydu","level":3,"time":"December 23, 2023 19:30:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"vZdUOEgS99WINXrCBydu","level":3,"time":"December 23, 2023 19:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"DxDvZlbqlIZ0cD0WZLDb","level":3,"time":"December 23, 2023 20:31:03","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"DxDvZlbqlIZ0cD0WZLDb","level":3,"time":"December 23, 2023 20:31:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"DxDvZlbqlIZ0cD0WZLDb","level":3,"time":"December 23, 2023 20:31:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"yU4x9SQjODtzvA6YnYh9","level":3,"time":"December 24, 2023 05:00:08","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"yU4x9SQjODtzvA6YnYh9","level":3,"time":"December 24, 2023 05:00:09","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"yU4x9SQjODtzvA6YnYh9","level":3,"time":"December 24, 2023 05:00:10","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"SzPDzRgiYncJgjzvsvic","level":3,"time":"December 24, 2023 06:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"SzPDzRgiYncJgjzvsvic","level":3,"time":"December 24, 2023 06:30:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"SzPDzRgiYncJgjzvsvic","level":3,"time":"December 24, 2023 06:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"sVrV0tuAHloCAwOqcmbK","level":3,"time":"December 24, 2023 08:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"sVrV0tuAHloCAwOqcmbK","level":3,"time":"December 24, 2023 08:00:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"sVrV0tuAHloCAwOqcmbK","level":3,"time":"December 24, 2023 08:00:08","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"YWW76LUp1Dxy0e5YqvyO","level":3,"time":"December 24, 2023 09:30:04","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"YWW76LUp1Dxy0e5YqvyO","level":3,"time":"December 24, 2023 09:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"YWW76LUp1Dxy0e5YqvyO","level":3,"time":"December 24, 2023 09:30:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"kSITd0FJBYhVb7KLMAZg","level":3,"time":"December 24, 2023 11:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"kSITd0FJBYhVb7KLMAZg","level":3,"time":"December 24, 2023 11:00:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"kSITd0FJBYhVb7KLMAZg","level":3,"time":"December 24, 2023 11:00:08","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"vP3M45gZ2mnAidQFYE7d","level":3,"time":"December 24, 2023 12:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"vP3M45gZ2mnAidQFYE7d","level":3,"time":"December 24, 2023 12:30:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"vP3M45gZ2mnAidQFYE7d","level":3,"time":"December 24, 2023 12:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"33H7Dxks7YSrFGXJa0HL","level":3,"time":"December 24, 2023 14:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"33H7Dxks7YSrFGXJa0HL","level":3,"time":"December 24, 2023 14:00:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"33H7Dxks7YSrFGXJa0HL","level":3,"time":"December 24, 2023 14:00:08","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"Mk6yAO42QvtsZKS1elpp","level":3,"time":"December 24, 2023 15:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"Mk6yAO42QvtsZKS1elpp","level":3,"time":"December 24, 2023 15:30:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"Mk6yAO42QvtsZKS1elpp","level":3,"time":"December 24, 2023 15:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"n2DhG1eyvNBoXL7CYgHf","level":3,"time":"December 24, 2023 16:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"PPOCkec3SKZPNCBjxLje","level":3,"time":"December 24, 2023 17:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"PPOCkec3SKZPNCBjxLje","level":3,"time":"December 24, 2023 17:00:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"yZt22wExuOeWFOHniCdM","level":3,"time":"December 24, 2023 18:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"yZt22wExuOeWFOHniCdM","level":3,"time":"December 24, 2023 18:00:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"yZt22wExuOeWFOHniCdM","level":3,"time":"December 24, 2023 18:00:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"gNWVZxrfwr3CzHJc01ok","level":3,"time":"December 24, 2023 19:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"gNWVZxrfwr3CzHJc01ok","level":3,"time":"December 24, 2023 19:30:06","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"gNWVZxrfwr3CzHJc01ok","level":3,"time":"December 24, 2023 19:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"6sdSrqYNN83AAToG0E1u","level":3,"time":"December 24, 2023 20:30:40","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"6sdSrqYNN83AAToG0E1u","level":3,"time":"December 24, 2023 20:30:41","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"g28raaqkxbzMsktFeKid","level":3,"time":"December 24, 2023 21:00:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"3GkYYcPHQKR3G7j0DXe9","level":3,"time":"December 25, 2023 05:00:12","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"3GkYYcPHQKR3G7j0DXe9","level":3,"time":"December 25, 2023 05:00:14","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"3GkYYcPHQKR3G7j0DXe9","level":3,"time":"December 25, 2023 05:00:15","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"e62Ix4yySzNwLFmHiktG","level":3,"time":"December 25, 2023 06:30:05","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"e62Ix4yySzNwLFmHiktG","level":3,"time":"December 25, 2023 06:30:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"e62Ix4yySzNwLFmHiktG","level":3,"time":"December 25, 2023 06:30:08","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"cJ8UmX6XcwBKjdfS7r4t","level":3,"time":"December 25, 2023 08:00:07","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"cJ8UmX6XcwBKjdfS7r4t","level":3,"time":"December 25, 2023 08:00:09","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}
{"reqId":"cJ8UmX6XcwBKjdfS7r4t","level":3,"time":"December 25, 2023 08:00:10","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Trying to access array offset on value of type bool at /var/www/nextcloud/apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php#776","userAgent":"--","version":"28.0.1.1","data":{"app":"PHP"}}

What it is caused by and how to resolve that issue?

Start at apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php line 776 and inspect the logged warning in the context of the IMAP client. Reproduce it with the configured onet.pl accounts on PHP 8.1 while checking the Nextcloud log. Done means the repeated array-offset warnings no longer occur during normal mail polling or use.