Nextcloud AIO is not the only way to run Nextcloud in docker. For example you can use the Nextcloud docker repository and docker-compose for which there are many examples. I’ve been running Nextcloud this way for many years now without any un-recoverable issues, and no issues at all that weren’t caused by me. Upgrading is also very easy since you simply increment the version in docker-compose.yml and restart the service.
That said the NixOS suggestion from @StrawberryPigtails@lemmy.sdf.org looks really neat and I may try that out soon my self since I’ve never played with NixOS before and it seems like a good excuse to do so.
Does Bazzite use a gamescope session on wayland by default? Gamescope has a bug which prevents the wayland client from drawing the steam overlay. I suppose it’s unlikely to be the same issue but I happen to be dealing with it on my system (not Bazzite) so I immediately made the connection.