All participants' connections went Closed (no reason) simultaneously mid-session

Video SDK
1

SDK: Zoom Video SDK for Web, @zoom/videosdk 2.4.2
Date/time: 2026-06-24 (UTC)
Session topic (tpc): 302baf7c-83e0-4d82-8119-7a81289c8973

It ran as TWO back-to-back session instances:
0jpu+6uvS76sd9W04TF1jQ==

MzCfDfhTWGm5EAmBDv0Fg==

In the first session, 4 of the 6 participants’ connections transitioned to ConnectionState.Closed within an 8-second window with no reason (the payload.reason was undefined — NOT ‘ended by host’, NOT ‘kicked by host’). Is it possible to see what caused this on your side?

The remaining clients then re-joined the same topic ~01:11Z, creating session B.

QoS was good right up to the drop (from the Reports /users/qos endpoint, per-minute, all 6 users): zero audio_socket_break / video_socket_break, 0.0% packet loss on every audio/video leg, latency 0–90ms, all on data center United States (SJC) over UDP, no CPU pressure. No degradation preceded the simultaneous close.

Our client behavior: init uses leaveOnPageUnload: true; the app only ever calls client.leave() (we never call client.leave(true)), so we never explicitly end the session. Every participant’s JWT is minted with role_type: 1.

Questions:

  1. What is the per-participant leave_reason (from the session.user_left webhook) for session ID 0jpu+6uvS76sd9W04TF1jQ== at 01:06:5xZ?
  2. With zero socket breaks / 0% loss, what would cause all clients to receive Closed (reason undefined) simultaneously and the session to terminate, when no client called leave(true)?
  3. Could leaveOnPageUnload: true + multiple role_type: 1 (host) participants closing/refreshing in the same window cause a server-side session reset? Is the “session ends when the original host leaves” behavior in play here?
2

Hey @Billy117

Thanks for your feedback.

0jpu+6uvS76sd9W04TF1jQ==

We found in the logs that between 01:06:51 and 01:06:59 UTC, 4 users did leave the session, and it was an active leave. Combined with leaveOnPageUnload: true, I suspect this option may have caused the session leave.

We had a similar case with another customer before. They had the video call embedded in an iframe page, and when the parent page unexpectedly updated the iframe src, the beforeUnload event was triggered inside the iframe, which caused the users who were originally in the session to leave.

Also, the multiple role_type: 1 participants you mentioned do not affect the session leave behavior.

Thanks
Vic