I know that this issue has already been opened (MDL-51262)
But here are some details of the same issue that I am facing currently. Hope this provides some more test cases for the developers to check for.
I am currently experiencing this in a large-scale offering (Close to 4000 registered learners).
I tried it twice to see whether there are some variations
The common workshop settings were for "Separate Groups" , Grouping: Custom Grouping that we had enabled for this group, Enable Scheduled Allocation : Ticked, Number of Reviews : 4, The number of members in individual group varies. [This was a Teacher Professional Development programme for Use of ICT and hence contained teachers from different domains]
The following was what I tried different:
For W1, when the switch was made to assessment phase there were people who got 16-20 assignments for review. There were 3 unallocated submissions.
For W2, when the switch was made initially there were 10-16 assignments per person and there were 5 unallocated submission. Now I changed the workshop back to Submission phase. Kept it open for some time (3 hours) and "Remove current allocations: Ticked". Now I observed that "To be allocated: 0" and saw that many have received 25-34 submissions.
Based on the experience of W1, we had specified that each one need to review only 4 more. But even then we have received queries from several confused participants.
I have yet another workshop (W3) that I will release in few hours. The submission for this is due in 5 days. I will try to update this post if I experience a completely different behaviour.