Crazy weird bug - seeing snapshot of another participant's past feed instead of video feed from one

We’re having a meeting right now on a self-hosted server. The moderator and I are next to each other on the same Wi-Fi. Some people had trouble connecting (black screens), so I joined from my browser quickly to make sure things worked, then I ended the chat.

On the moderator’s screen (Firefox on Windows)

About 5 minutes later, someone else joined, from a completely different location and network. Their video feed is a static screenshot of me as I appeared as one point during that quick check. Let’s call them the “ghost”.

This is not any sort of intentional bombing, that person is actively participating in a discussion (audio only, their blue speaker icon appearing as expected when they speak) but non-technical and doesn’t know what’s going on. The gallery view looks normal, except their video feed is a snapshot from my past brief video incursion. Their connection indicator is red. After ~10 minutes, their feed went black, and the connection indicator went green. 5 more minutes later, back to that same static shot from my feed, with a red connection status icon.

On my screen (Chrome on Ubunutu)

About 10 more minutes later, I joined again. I did see the video feed of the “ghost” normally for ~10 seconds, then it froze. So the ghost was not doing anything weird like trying to use a screenshot as their static video feed (if that’s even possible with Jitsi at all). 5 minutes later, the ghost’s feed is just as frozen (but not black), and their connection indicator is grey.

On the server

We use a Digital Ocean VPS with 2GB RAM. There are only 6 participants, the CPU utilization is 25%-30%, and the memory usage is 650M/2GB in htop and 45% in the DO dashboard. Load is around 0.3. The public bandwidth is 7.5 - 10 Mbps.

Questions

  1. Is it possible at all that Jitsi “remembered” a frame from my feed and that got stuck instead of the video feed of the moderator? Could the web app do that, or could Jitsi Meet cross its wires like that?
  2. What bandwidth profile should be expected for 5-6 participants?