> The connection with Firefox (on Linux) regularly breaks.
If the connection breaks, the green button in the username field that fills in your details, turns into a red cross. If you just click the red cross, keepassxc will immediately reestablish the connection. Then click again to fill in. For me, I only have to do this once after unlocking my database.
Sorry, I don't use Linux much, so I don't have a recommendation. But one of the key advantages of a Keepass-Database is that theres loads of clients, so maybe try another.
The connection with Firefox (on Linux) regularly breaks. There's lots of subtle bugs and the UX just isn't on the same level.
I'll also happily jump ship if something better comes along that's open source, has great browser and android integration and self hosted.
I'm also eying Bitwarden / Vaultwarden but migration is a pain