Hello.
I can successfully switch the display device the game is running on, and I can control whether or not the game is Fullscreen windowed or windowed. This works fine.
If I switch from a 4K display to an HD display, (or simply from a larger resolution to a lower one) I reduce the window size to fit whilst maintaining fullscreen windowed mode. This too works fine.
What doesn’t seem to work is if I try to switch back to the larger screen. The window will stay at the lower window size, even though it should be fullscreen.
Trying to call UGameUserSettings::SetFullscreenMode doesn’t work as it checks to make sure the screen mode has changed before changing it, so doesn’t do anything.
Also, calling UGameUserSettings::RequestResolutionChange doesn’t seem to work either.
Trying to set the display mode to windowed, then back to fullscreen windowed also doesn’t seem to work, it just stays appearing like a smaller window.
(I’ve also tried GEngine->GameViewport->GetWindow()->SetWindowMode, but it too doesn’t do what I’m after.)
Is there anything I can do to force the game window to retain its ‘fullscreen-ness’?