Undo shortcut isn't working

What do you see in the History panel?  Does it have previous step content?

I have had some issues around window focus with the beta version, so click on the document window to make sure it has content.

Check Edit > Keyboard Shortcuts to see things are as they should be.

Hi @responsible_calmness2468 please share more info on what you are seeing, your workflow or anything else that might help us to determine what is happening.  Screenshots or video of your workflow showing the issue is very helpful.

Thanks,

Cory - Photoshop Product Manager