Whenever I undo in Krita with the ctrl + z shortcut, it draws this straight line halfway across the canvas. I am using an H420 Huion drawing tablet by the way on a MacBook Air.

Sometimes this is not a problem, but when it is, it usually causes Krita to lag and freeze up a lot. Is there a reason why the straight line is coming up when I press ctrl? Or is it just because I have a cheaper drawing tablet?

Thanks

D

Undo on macOS is command-z?