Lost the ability to sort by ticket owner

Lost the ability to sort by ticket owner

Hi all, in the last week or so, we have lost the ability to sort tickets by Ticket Owner. Unlike the other columns which we can hover over and click on to sort, Ticket Owner is no longer clickable. Is it just us, or are other customers seeing this too? This was a very handy tool for our individual teams to see at-a-glance which tickets in their queue don't yet have a specific owner, and we haven't changed anything in our configuration which we could link to this loss of functionality.