Every night i use the appdata-backup to stop, backup, check for updates and restart my nextcloud-ffmpeg container. Most of the mornings after i am greeted with an error explaining the data directory is readable by other users suggesting to change the folder permissions to 0770. The folder permissions as visible from within the container are drwxrwx---.
The only thing notices that has changed is the owner of the data folder(volume) in the docker container, when i change it back with chown www-data:www-data data (from within the container cli) the error goes away. Perhaps relevant: the data volume is mapped to a different share ("nextcloud").
Any suggestions on debugging this issue?