One docker container influences other docker container

Preparations:

- deleted all nextcloud dirs under /mnt/user/appdata

- deleted all previous installed nextcloud apps in CA apps menu (which deletes the nextcloud user templates)

Now I installed Linuxserver's Nextcloud container and changed the settings as follows:

Installs as usual:

Then I parallel installed knex666 Nextcloud container as follows:

Now this bug happens (all output is in separate lines):

And version is "not available":