I also have this problem and have been working with Apple support to try to resolve it. For me it happens whenever:
- I try to take an app to full-screen mode
- I try to animate between Desktop Spaces using the mouse (two-finger swipe), trackpad, keyboard commands, or anything else that causes the Desktop Space to switch.
- I watch a video in full-screen mode
I think the unifying thing here is the automatic switching to a different Desktop Space, including for full-screen. Interestingly, if I navigate Desktop Spaces manually, usuing Mission Control, I'm successful in switching.
Of note, this is only affecting my account. I created a "test" account and everything works fine. Apple thinks it's something that's loading during my unique login and we're working on isolating the problem.
You may want to try the Desktop Spaces movement on your computer. If you have the same problem, we may have the same issue. If (when) I get a resolution from Apple, I will post here. BTW, you may want to create a "test" account and try going to full-screen mode with an app, and navigating spaces. If it works, you've isolated the problem to some idiosyncracy in your account.