I used the "reassign" feature in the past, but it suddenly stopped working. I can see the field, if I click on it, I get a dropdown. From the dropdown, I can select the new Assignee. So far so good. But upon selecting it, the dropdown stays a dropdown (rather than turning back into text, as it should upon successful submission). And sure enough, if I refresh the page, the item is still assigned to me.
This used to work in the past, and all other features still work.