What proccesses updates UWQ items after ownership change?

Hi

I changed ownership of some customer work items using Collections Administator in Advanced Collections, I then ran the IEX Populate UWQ Tables concurrent request and the items moved to the right collector.

I decided a couple of these items should have gone to another collector so went back to Collections Administator in Advanced Collections and tried to change the ownership again, this time pressing the update button against the selected line didn't make any difference and the lines stayed in the ownership of the same collector.

I then ran the following concurrent requests and afterwards I could change the ownership of the work item to another collector.