Report came in from one of our engineers:
I'm having an issue with reordering my tasks from within a search result page. This might not be an actual feature of maniphest (I'm curious how it works, really, if it is, but I love the concept so I've been trying it out optimistically so far), so it could be the fix is just to remove the ability to reorder.
- Go to a saved search result
- Reorder some tasks within a group by grabbing them and dragging them up or down the list
- Refresh the page -> the ordering returns back to what it was (afaict, random within a priority)