This was an issue on v11 and is even worse on v11.0,10. The GUI will freeze. MIDI and audio continue to be passed but the screen is completely locked up, no VU meters move, menus do nothing, etc. I do not have this problem on Cubase 10 so it is something in 11. It will do this with all plugins disabled, and even preferences reset.
I’m running Windows 10 20H2 but it was on my last patched version of Windows as well. NVidia graphics card, AMD 5900x CPU.