Calendar will not complete loading

Steps to reproduce

1. Open calendar from top bar after download/enable

Expected behavior

Calendar should open and allow entry

Actual behaviour

Calendar never completes the load - each calendar just shows a spinning circle

Calendar app version

4.7.16

CalDAV-clients used

basic nextcloud AIO web

Browser

firefox/vivaldi/opera all same

Client operating system

debian linux

Server operating system

AIO docker

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

29.0.6

Updated from an older installed version or fresh install

Updated from an older version

List of activated apps

128beb82b29b:/var/www/html# sudo -u www-data php occ app:list

Warning: Failed to set memory limit to 0 bytes (Current memory usage is 2097152 bytes) in Unknown on line 0
The current PHP memory limit is below the recommended value of 512MB.
Enabled:
  - activity: 2.21.1
  - admin_audit: 1.19.0
  - appointments: 2.1.10
  - calendar: 4.7.16
  - circles: 29.0.0-dev
  - cloud_federation_api: 1.12.0
  - comments: 1.19.0
  - contacts: 6.0.0
  - contactsinteraction: 1.10.0
  - dashboard: 7.9.0
  - dav: 1.30.1
  - deck: 1.13.1
  - federatedfilesharing: 1.19.0
  - federation: 1.19.0
  - files: 2.1.1
  - files_downloadlimit: 2.0.0
  - files_external: 1.21.0
  - files_pdfviewer: 2.10.0
  - files_reminders: 1.2.0
  - files_sharing: 1.21.0
  - files_trashbin: 1.19.0
  - files_versions: 1.22.0
  - firstrunwizard: 2.18.0
  - logreader: 2.14.0
  - lookup_server_connector: 1.17.0
  - maps: 1.4.0
  - nextcloud-aio: 0.6.0
  - nextcloud_announcements: 1.18.0
  - notifications: 2.17.0
  - notify_push: 0.7.0
  - oauth2: 1.17.0
  - password_policy: 1.19.0
  - photos: 2.5.0
  - previewgenerator: 5.6.0
  - privacy: 1.13.0
  - provisioning_api: 1.19.0
  - related_resources: 1.4.0
  - richdocuments: 8.4.6
  - riotchat: 0.18.0
  - serverinfo: 1.19.0
  - settings: 1.12.0
  - sharebymail: 1.19.0
  - spreed: 19.0.9
  - support: 1.12.0
  - survey_client: 1.17.0
  - systemtags: 1.19.0
  - tasks: 0.16.1
  - text: 3.10.1
  - theming: 2.4.0
  - twofactor_backupcodes: 1.18.0
  - twofactor_totp: 11.0.0-dev
  - user_status: 1.9.0
  - viewer: 2.3.0
  - weather_status: 1.9.0
  - workflowengine: 2.11.0
Disabled:
  - bruteforcesettings: 2.9.0
  - encryption: 2.17.0
  - files_rightclick: 0.15.1 (installed 1.6.0)
  - recommendations: 2.1.0 (installed 1.4.0)
  - suspicious_login: 7.0.0
  - user_ldap: 1.20.0

Nextcloud configuration

128beb82b29b:/var/www/html# sudo -u www-data php occ config:list system

Warning: Failed to set memory limit to 0 bytes (Current memory usage is 2097152 bytes) in Unknown on line 0
The current PHP memory limit is below the recommended value of 512MB.
{
    "system": {
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "overwritehost": "aio.b3lt3r.com",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "aio.b3lt3r.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "29.0.6.1",
        "overwrite.cli.url": "https:\/\/aio.b3lt3r.com\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "loglevel": 0,
        "log_type": "file",
        "logfile": "\/var\/www\/html\/data\/nextcloud.log",
        "log_rotate_size": "10485760",
        "log.condition": {
            "apps": [
                "admin_audit"
            ]
        },
        "preview_max_x": 2048,
        "preview_max_y": 2048,
        "jpeg_quality": 60,
        "enabledPreviewProviders": [
            "OC\\Preview\\Imaginary",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\MP3",
            "OC\\Preview\\TXT",
            "OC\\Preview\\OpenDocument",
            "OC\\Preview\\Movie",
            "OC\\Preview\\HEIC",
            "OC\\Preview\\TIFF"
        ],
        "enable_previews": true,
        "upgrade.disable-web": true,
        "mail_smtpmode": "smtp",
        "trashbin_retention_obligation": "auto, 30",
        "versions_retention_obligation": "auto, 30",
        "activity_expire_days": "30",
        "simpleSignUpLink.shown": false,
        "share_folder": "\/Shared",
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
        "htaccess.RewriteBase": "\/",
        "files_external_allow_create_new_local": true,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "allow_local_remote_servers": true,
        "default_phone_region": "GB",
        "skeletondirectory": "\/mnt\/external\/aio\/skeleton",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_sendmailmode": "smtp",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "updatedirectory": "\/nc-updater",
        "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
        "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
        "davstorage.request_timeout": 3600,
        "dbpersistent": false,
        "appsallowlist": false,
        "data-fingerprint": "4f2e8bb88369023f37adc17dfcacfe6b",
        "maintenance_window_start": 100,
        "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
        "auth.bruteforce.protection.enabled": true,
        "ratelimit.protection.enabled": true,
        "memories.db.triggers.fcu": true,
        "memories.exiftool": "\/var\/www\/html\/custom_apps\/memories\/bin-ext\/exiftool-amd64-musl",
        "memories.vod.path": "\/var\/www\/html\/custom_apps\/memories\/bin-ext\/go-vod-amd64",
        "memories.vod.ffmpeg": "\/usr\/bin\/ffmpeg",
        "memories.vod.ffprobe": "\/usr\/bin\/ffprobe"
    }
}

Web server error log

No response

Log file

No response

Browser log

I did a comparison between the working and failing instance looking in the browser console. In the working I see no errors when the calendar is selected. In the failing instance I see 404 which seem to be complaining about the DAV server.

<====== console output ======>
calendar home scanned Array(5) Array(1) Array(0)
/remote.php/dav/calendars/mike/personal/:1

   Failed to load resource: the server responded with a status of 404 (Not Found)
index.js:612 Error
at o.onreadystatechange (dist.js:2:17483)
(anonymous) @ index.js:612
<==========================================>

If I select the dav link from the settings on working side and open a browser I get a sign-in dialog as expected, doing the same on failing side I get:
internal Server Error

The server was unable to complete your request.

If this happens again, please send the technical details below to the server administrator.

More details can be found in the server log.
Technical details

Remote Address: 192.168.100.6
Request ID: OQsgkCk3TZSpNdXJljF
and the log shows:

Error	remote	Forbidden Requested uri (/remote.php/dav?) is out of base uri (/remote.php/dav/)
In both instances the URL used is https://domain.com/remote.php/dav

This seems to me that dav is not configured correctly in the failing side but appreciate your view 

Many thanks

Additional info

I have two identical AIO instances - one works the other doesn't - the log above is taken from the failing side.

Start by comparing the working and failing AIO instances, then inspect the browser request to /remote.php/dav/calendars/mike/personal/ and the Nextcloud remote log showing the base-URI error. Done means identifying the DAV configuration difference and restoring calendar loading without the 404 or internal server error.