In an assignment collection with subassignments, when the assignment collection itself has already assigned the graders, and new subassignments are added or made gradable (e.g. by adding a checklist).
Clicking Assign graders does not try to assign graders to the newly gradable subassignments.
Instead, you have to Unassign and Assign to get it to work.

Submitted by D. Pelsmaeker on 3 October 2019 at 22:47