Thanks @otwieracz.
Firstly - I didn’t remove the container correctly. It seems like deleting its configuration from the configuration.nix is not enough you need to remove /var/lib/containers/{name} Which caused my issue.
Secondly - I missed bindMount when trying to change services.nextcloud.home.
@FantasyCookie17 how about trying nextcloud in nixos container? So you can be sure to have clean environment?