Can't drag titlebar of window to next screen
For some reason, no Finder no web browser window will let me drag the titlebar of the window to move it around. It shifts maybe a few pixels, but if I want it to move to my extended display it refuses to do so even with my window not maximized or kiosk mode. This is happening in High Sierra 10.13.6 on an iMac 11,3 (the maximum OS for the computer. It used to work just fine. Now, even though the mouse cursor will navigate to the adjacent display, I can't make windows open on the adjacent display. What's going on here?
Current Pro Desktops