I use 3 monitors, generally 2 at a time. Sometimes When I switch from using 1 and 2 (1 is primary) to using 2 and 3 (3 is primary), then whenever I go to maximize a window, the window fills horizontally, but only half the screen height. Only fix I can find is exit displayfusion and restart. I'm using Windows 10.

Doesn't happen all the time, but figured out it had something to do with maximized video on monitor #2. If I go to the video window and undo maximize, the the unmaximized version lands partially on the opposite side of monitor #3 for a second, then pops back onto monitor #2. Then I can maximize it again and everything on monitor #3 behaves normally.

In any case, not a big deal now that I can get out of it.