Shortcut Stepbackward doesn't work

Ever since the new update the shortcut for step backward (alt + ctrl + z) doesn't work. I hear the sound it's supposed to make, I've checked the keyboard shortcuts to see if it's still the same combination, which it is. It just doesn't work. and if it does work, it's like a minute later or so. Has anybody else had this problem and been able to fix it?

I can go a step back by clicking on step backward in the edit menu, but it just takes too much time in the long run.