Ditto. This is on a MacStudio M1 with 2 4K displays (3840x2160), running macOS 12.6 (Monterey). App launches and while in the foreground (full screen or windowed) the main display draws with toolbar, etc., and then a big, flickering magenta square in the middle of the screen. The in-window controls are inop, but the app's menubar responds to events to resize the window or quit. The problem is present regardless of other apps running, fresh reboot, etc.