For about a week I've had irregular issues with BitWarden on Firefox, prior to the recent FF update and since I installed it. It can't connect to the web vault occasionally, the spinning wheel is left hanging at sign-in. At the same time I can connect to any other site I've tried so I'm pretty sure that its not my connection that has an occasional outage. I've not found the same issue when using Brave. I can't see anything in their forums that would help me or you with your issues.