If I have content tabs open on two displays, Full Screen Preview doesn't work

Using version 13.0.2.636

I have content tabs spread across two displays. I noticed recently that spacebar-full screen preview would'nt load the image, going full screen, but remaining blank.

On a hunch, I closed the content tabs on the secondary display. Full screen worked again. I reopened those content tabs. Full screen stopped working. I moved all the content tabs to the primary display. Full screen worked again. 

I didn't have to choose between using both displays and having full screen previews before. It's not the only workflow-killer to crop up in recent versions of Bridge, but this one doesn't seem deliberate so perhaps there's a chance to plead for it to behave as before.