This has something to do with server overload but not completely.
We use workshops extensively and they all move automatically from submission to assessment phase at the same time. Scheduled allocation of 3 peers is then triggered.
It has been happening since forever, but in more extreme form lately, that instead of allocating three peers per submission, people are allocated 6, 9, 15, 19 and even 21 peers!
There is some kind of bug that re-triggers the running of the allocating task. Have you had this experience?
This is not like allocating 4 instead of 3, or 2 instead of three, which is sometimes caused for lack of peers in the group. This is an actual bug that occurs now in every course every week for us.