Can't delete file locally and in Nextcloud web-interface - file is present on database and remote on disk

Thank you for your help.

I increased the log-level to 0 in config.php
Now, which log you mean? When I go to XXX/index.php/settings/admin/logging there doesn’t seem to be anything related to my action trying to delete the file. Just this, but I think it’s not related:

Exception dirty table reads: SELECT * FROM *PREFIX*jobs WHERE (reserved_at <= :dcValue1) AND (last_checked <= :dcValue2) AND (time_sensitive = :dcValue3) ORDER BY last_checked ASC LIMIT 1

Are you forbidding any file types/names/extensions on either the client-side or server-side?
No, no that I know of…

I discovered that there are more files, that are present remotely on my webspace/Nextcloud when accessed via Web-Interface and not present on my laptop locally (client log gives again 403 error). When I try to delete these files remotely via Web-Interface there’s the same error.

Is this maybe related to these issues here, where there are orphaned entries? I couldn’t really understand the solution:

Thanks!