User still in member list after leaving (with LL enabled)

[erikjohnston]

I have a room with a bunch of people, someone left the room but they still appear in the right hand panel.

[bwindels]

I've asked Erik for more specifics: it was a room with around 11 people, the ones that left and still appeared in the memberlist where not active before leaving, and he only saw it once. The home-server of the account which with it happened with was on HS jki.re. The members appeared left in the timeline but not in the memberlist. No rageshake available.

[bwindels]

I've tried manually reproducing this, and have written e2e tests that try and repro this, both unable to repro.

[erikjohnston]

(It's also possible this is a synapse issue, though it seemed more likely to be riot web.)

[bwindels]

The only thing that I can think off is that an exception occured after loading the members before this._listenForMembersChanges(); got called. Would be very helpful to get a rageshake if this happens again. Going to park it for now.