[2.7] Phantom user bug

[Arthurk12]

Describe the bug After a user is promoted to moderator, previously disconnected users who have sent messages in the chat reappear in the user list.

To Reproduce Steps to reproduce the behavior:

1. Join meeting with 3 sessions: one moderator(m1) and two viewers(v1 and v2)(in anonymous tabs);
2. In v1 session, send a message in the public chat and leave by closing the browser tab;
3. Wait for user v1 to be removed from the user list (approximately 10 seconds);
4. In m1 session, promote v2 to moderator;
5. See error: in v2 session, the user v1 shows up in the user list again;

Expected behavior After the user list updates, only online users should be displayed.

Actual behavior Offline users who have previously sent messages in the chat reappear in the user list after a moderator promotion.

Screenshots

BBB version: dev27.bigbluebutton.org

[Ithanil]

Related/duplicate of https://github.com/bigbluebutton/bigbluebutton/issues/19564

[antobinary]

Closed via #20253