Hi i’m developing a 3rd person shooter with split screen multiplayer, and when we implemented the hud with UMG we discovered a really wierd behaviour, if executed in the editor everything worked perfect, but if you used Fullscreen after a few seconds, except the last screen to receive the widget, the other screens stopped refreshing and every frame stairs painted and the new one pains on top.
Playing in the editor
playing in full screen
some more data: this also happens when you generate the .Exe, and while in full screen each time the focus on the screen changes( lose focus, recive focus) it refreshes.
here is a video to the issue:
https://drive.google.com/open?id=0B9JIoBfE_81EUlpEZTVqOWJBQmM