It's not obvious that this is an issue with the WebRTC sessions themselves. If a server is responsible for muxing the streams, each client could be in a properl

It's not obvious that this is an issue with the WebRTC sessions themselves. If a server is responsible for muxing the streams, each client could be in a properly negotiated session with the server, and due to an internal software defect with how the server renders the streams for a client, the client could experience exactly the symptoms you describe.