only thing I normally change for a new project is Scalable graphics instead of Max Quality or whatever it says. Screenshot attached. I also changed no settings post-upgrade. This issue occurs on my current projects, and new blank projects (Blueprint).
I did some testing with settings you mentioned, and it appears to correlate with Resolution Scale. If I set it to 50%, I see half of screen, if I set it to 100%, I see whole screen. It’s a bug, but it has a workaround. Yay!