Unity UI displays incorectly

After installing Unity, I found an issue with the UI where the panes would display incorrectly, showing other panes and the contents of other windows.

This video demonstrates this problem: Unity Problem - YouTube

Is there any way to fix this?

I have the same problem, I’ve had it for over a year now and nobody seems competent enough to solve it. Unity is losing money from people who might buy pro if they can’t even make a working UI.