I don’t know what causes that but I’d guess there’s a gfx card issue - perhaps the Java subsytem is having issues with your card?
I had a similar issue a few days ago (but not using Spy, just running a test) and Katalon trashed my whole display. Following that, evvery time I started a test, one monitor would go black. But mine was COMPLETELY black, yours is not going by your screenshot.
@duyluong ideas?