Quick WebRTC Video Stream Fix

The WebRTC flow in my Node-/JavaScript app is almost complete, but the remote video never appears in the browser on desktop. Signaling connects, audio sometimes negotiates, yet the video track stays blank. I need a fresh set of eyes to trace the SDP / ICE exchange, identify the break-point (STUN, TURN, or media track attachment), and patch it so the peer connection renders video as expected.

Tech context
• Node.js backend that handles signaling
• React front end (plain JS components in places)
• Standard STUN server already configured; TURN available for fallback

Scope of work
1. Inspect the existing signaling and media flow.
2. Pinpoint why the video track is lost or never attached.
3. Implement the minimal code change(s) necessary to restore video on desktop browsers.
4. Send me a concise summary of what was wrong and how you fixed it (a few paragraphs or inline comments).

Acceptance criteria
• Refreshing the page on desktop shows the remote video within 2–3 s.
• No console errors related to WebRTC after the fix.
• Your explanation lets me reproduce or adjust the solution later.

This should be a fast debug session for someone comfortable with SDP munging, onicecandidate handling, and attachMediaStream, so I’m aiming to wrap it up within a few hours of kickoff.