I have exactly the same problem.
When I run ./runheadless.webrtc.sh on a container, the browser shows the same grey screen as above but it does nothing when I press the play button. This is the same even if I try to access the docker from the same PC (e.g., localhost).
Some further information:
- WebRTC works if I start it from the native app (and connect to it locally, on the same network, and across networks with VPN).
- On Docker, websocket and native stream work well (if I connect to it locally, on the same network, and across networks with VPN).
Are there some further WebRTC settings needed specifically for the containers?