New Teams App

I don't know where to start! I have been at this for two days now. I had support from Microsoft for two hours, but this did not solve my issue. When I switch my IMac to the new TEAMS app, participants can't hear me, but I can hear them. When on the same app in my browser, there is no issue at all, and there is no issue on my other Mac.

One thing I have noticed is that when I go to devices in settings (on this PC or Mac), it is not allowing me to customise the setup. I am the admin, so I don't think its a permissions issue. I have also been in the terminal, trying to follow the advice given in another post.