The image captured is the desktop background instead of the forefront application. This occurs not matter if you capture the area, window, or full screen. CTL+SHIFT+4, the native OS X method works correctly.
Mac OSX 10.15.4
Retina 5K 27inch
Please close issue. Greenshot was damaged after an update. Reinstalling it fixed it. Even though Greenshot was check in the “allow access” dialog, it really wasn’t allowed.