I spent two hours today trying to figure out why Nextcloud couldn’t read my data directory. Docker wasn’t mounting my data directory. Moved everything into my data directory. Docker couldn’t even see the configuration file.
Turns out the Docker Snap package only has access to files under the /home directory.
Moral of the story: never trust a Snap package.
I have stopped using Ubuntu because of this and other Canonical nonsense. It used to be the best too. For a workstation, Mint Cinnamon, for a server Debian headless. God speed with the rest of your setup