Transparent app window with shadow in the middle of display

This transparent box appeared after the sequoia update and can't seem to get rid of it. If I restart the computer after some minutes it would reappear again. Haven't been able to find a fix for this.

I can't scroll when the mouse is pointing on the box and right clicking doesn't do anything. It gets kinda annoying when a pop up prompt shows up exactly in the middle of the screen since I won't be able to click any buttons under the transparent box.