Desktop window preview doesn't hiding when closing the tab

I just installed ubuntu 20.04, i just open app and triple tap (close window) the window is closed but not with the window preview. i have switch mate tweak but not affected. how to resolve this ? thx anyway


have you also tried changing the theme as well as the desktop after using Mate Tweak?. Also, what GPU do you have and have you installed any drivers?. :thinking: