Self-hosted Unified Beta backup - help

Hi! I think I'm going crazy. I've set up the Bitwarden Unified beta on my k3s cluster, running with an external PostgreSQL database. Before I fully commit to this setup I want to have a backup strategy in place.

Whatever I do, I can't seem to get it running from any sort of backup. The issues I'm having are similar to what I saw when setting it up and redeploying a few times: when I try to log in I just get a couple of 500s and I can't find any relevant information anywhere. Running a new deployment using the same installation ID and key, and the same database (or a clone of it) does not seem to work. Same thing with a new installation ID. Also backing up `/etc/bitwarden` and restoring that either before or after first startup does not help.

Does anyone have any experience with this? What do I actually need to copy to make sure the new/restored instance can access the old vault? Docs are very lacking on this front, and all I find when trying to google the issue seems to be "backup the database", which clearly isn't enough.

Any pointers or insight much appreciated!