Might be the same issue for me, Firefox 137.0 on Linux.

When I click on a room, the URL changes, indicating I might have joined the room, but I don't get any audio. No audio icon on the tab. Can't hear anything.

Console says "WebRTC: ICE failed, add a TURN server and see about:webrtc for more details"

I don't have WebRTC specifically disabled that I recall, I thought I've taken video calls in this Firefox before. Hope this report helps!