If you got the automatic updates on the bitwarden clients, they will show an empty vault if you are selfhosting vaultwarden.
It seems to be an accidental bug in the bitwarden clients that are assuming that they’re talking with official servers
It’s fixed with the latest release of the vaultwarden server that was published a few minutes ago
Such bugs have already appeared in the past. It’s only logical that this happens from time to time, as the creators of bitwarden don’t test the compatobility with 3rd party servers.
What is important is that they’re not deliberately blocking vaultwarden.