WebIDE: WebRTC bridge broken until local storage is modified/reset

Is there some logging of the phone javascript side where this WebRTC part runs?

It should be about the same logging as in the IDE (IIRC it's the same code) so it's worth a try connecting by USB and using chrome://inspect-devices

... but you could try some other webrtc examples with your phone like https://peerjs.com/examples? If they fail there's not much I'll be able to do!