My mouse is slightly offset from my brush/tool in Krita. Every time I need to click or paint, I have to shift my aim down about 20px. Also, can't see the top of the window where all the menus are. I tried resetting in krita config. No joy. Please note this doesn't depend ofn the device I'm using (pen, mouse, even trackpad). Any fix please?

What OS? Which version of Krita? Do you use a drawing tablet? Has that been calibrated? If you're on Windows, have an Intel GPU and your Krita is recent enough does the problem go away if you set the canvas rendenrer to Direct3D (Angle) in the Display page of the settings dialog? If so, it's this FAQ entry that's relevant: https://docs.krita.org/KritaFAQ#Krita_s ... _Intel_GPU.

This definitely sounds like the rather popular Intel OpenGL driver bug. If you use Krita 3.3.3 it should already have ANGLE selected by default. If you are using an older version, please consider updating to the latest.