I have run into the same issue. Sometimes my mic will work and then it doesn't. the change can happen within the one session without any hardware or software alts being made. During the session, i can go to Windows 10 voice recorder and make recordings but it is not working in reforger. I was in a session when my mic stopped working, exited, reinstalled app and mods, returned to the session and the mic worked. The next session it worked for a while and then stopped.