Received an insane amount of m.room.member state event as part of an incremental sync (MatrixHQ)

[BillCarsonFr]

Causing Element Android to fail for ever retrying to process the sync.
element-hq/element-android#5162
At this point it's at least 60k+ m.room.member state event for that incremental sync

Looks like changing the ACL did provoke that

[erikjohnston]

Looking at the rageshake and the matrix.org database it looks like the sync for HQ was gappy, but there were only ~100 state changes. I think something odd is going on, so have added some logging in #12068 (and to the android client to log sync tokens).

Please shout if anyone sees something like this again.