Hi, I don't know why this happens.
I have this graphic in the editor, the graphic has "Destination in" activated.
If I deactivate "Fullscreen in browser" I get this in execution (the black turned gray):
If I activate "Fullscreen in browser" and use "Letterbox integer scale" for example, then everything ok in execution:
Well, why does black turn gray when I deactivate "Fullscreen in browser"?