This happened to me several time in my early days with Bitwarden browser addon. I would create an entry and copy paste the password to the site before clicking save. The addon would loose the context when loosing focus and the entry was gone. I had to do several password reset after creating new entries because of this. I think they fixed this or I just got used to the flow.

To answer the last part of your post:

So far my experience is that the RCS-iMessage feature is working (or not) depending on the Apple user’s provider. I’m on Android with a “cheap” provider in Canada and RCS-iMessage work with my iMessage contacts that are on major providers but those on cheaper providers don’t work yet.

So if you are on Android and your basic RCS works you should be good.