Permission denied when adding a calendar entry

Get the following error when trying to add a calendar entry. this is wit imap auth. and a none docker install.

[2025-05-09T18:11:19.551499+02:00] request.INFO: Matched route "dav". {"route":"dav","route_parameters":{"_route":"dav","_controller":"App\Controller\DAVController::dav","path":"9c2db8d1cc9c512722ccfa8d09da6310d97722aa.ics"},"request_uri":"http://10.140.1.21/dav/9c2db8d1cc9c512722ccfa8d09da6310d97722aa.ics","method":"PUT"} []
[2025-05-09T18:11:19.555882+02:00] security.DEBUG: Checking for authenticator support. {"firewall_name":"main","authenticators":1} []
[2025-05-09T18:11:19.555922+02:00] security.DEBUG: Checking support on authenticator. {"firewall_name":"main","authenticator":"App\Security\LoginFormAuthenticator"} []
[2025-05-09T18:11:19.555945+02:00] security.DEBUG: Authenticator does not support the request. {"firewall_name":"main","authenticator":"App\Security\LoginFormAuthenticator"} []
[2025-05-09T18:11:19.848467+02:00] app.ERROR: [403]: Sabre\DAV\Exception\Forbidden - Permission denied to create file (filename 9c2db8d1cc9c512722ccfa8d09da6310d97722aa.ics) [{"file":"/var/www/davis/vendor/sabre/dav/lib/DAV/Server.php","line":1098,"function":"createFile","class":"Sabre\DAV\Collection","type":"->"},{"file":"/var/www/davis/vendor/sabre/dav/lib/DAV/CorePlugin.php","line":504,"function":"createFile","class":"Sabre\DAV\Server","type":"->"},{"file":"/var/www/davis/vendor/sabre/event/lib/WildcardEmitterTrait.php","line":89,"function":"httpPut","class":"Sabre\DAV\CorePlugin","type":"->"},{"file":"/var/www/davis/vendor/sabre/dav/lib/DAV/Server.php","line":472,"function":"emit","class":"Sabre\DAV\Server","type":"->"},{"file":"/var/www/davis/vendor/sabre/dav/lib/DAV/Server.php","line":253,"function":"invokeMethod","class":"Sabre\DAV\Server","type":"->"},{"file":"/var/www/davis/src/Controller/DAVController.php","line":333,"function":"start","class":"Sabre\DAV\Server","type":"->"},{"file":"/var/www/davis/vendor/symfony/http-kernel/HttpKernel.php","line":183,"function":"dav","class":"App\Controller\DAVController","type":"->"},{"file":"/var/www/davis/vendor/symfony/http-kernel/HttpKernel.php","line":76,"function":"handleRaw","class":"Symfony\Component\HttpKernel\HttpKernel","type":"->"},{"file":"/var/www/davis/vendor/symfony/http-kernel/Kernel.php","line":182,"function":"handle","class":"Symfony\Component\HttpKernel\HttpKernel","type":"->"},{"file":"/var/www/davis/vendor/symfony/runtime/Runner/Symfony/HttpKernelRunner.php","line":35,"function":"handle","class":"Symfony\Component\HttpKernel\Kernel","type":"->"},{"file":"/var/www/davis/vendor/autoload_runtime.php","line":29,"function":"run","class":"Symfony\Component\Runtime\Runner\Symfony\HttpKernelRunner","type":"->"},{"file":"/var/www/davis/public/index.php","line":10,"args":["/var/www/davis/vendor/autoload_runtime.php"],"function":"require_once"}] []

Start with src/Controller/DAVController.php at line 333 and the DAV request and authentication log entries; trace the PUT request for the .ics filename and inspect the permission failure reported by Sabre DAV. Reproduce the non-Docker IMAP-auth flow and confirm that adding a calendar entry no longer returns 403.