There is a temporary workaround involving adjustments to graphics card settings over on the Steinberg Cubase forum (https://forums.steinberg.net/t/graphic- ... /876276/75). If you're lucky, it might be applicable to your graphics card.
I've given up on Cubase 13 for now and have gone back to 12. I don't think Steinberg "get" Windows as a platform. Hence the weird caption bar menu thing on 12 and the UI problems in 13 that went unnoticed during development/testing/beta by Steinberg.