I do have a problem when starting games (Snes games with Snes 9x) in launchbox/Bigbox. When a game starts, the emulator starts in it's own window, and launchbox/Bigbox is going black.
The picture is taken after I click on the black screen. First screen popping up is "Game Over" and then the screen in the picture. I have moved the emulator screen on top of BigBox.
The only thing I have done in the emulator config is setting up the controller (a wireless Xbox One S).
If more info is needed, please let me know.