Maybe try it out on standard Firefox as a quick test? While annoying, this would help validate that the issue is with the librewolf changes to standard Firefox.
Also note that I also use both proton mail and drive from librewolf. Even today. If it’s a general issue with this setup, it hasn’t hit my machine (yet)
I recently moved away from Bitwarden to proton pass. I really only moved because I was already paying for proton unlimited for other services. That said, it’s been great. Does everything I need it to quite well on IOS and as a browser extension on Linux