I’m using Cubase 9 with Windows 10 on a Dell laptop and second monitor. I have a laptop with a high resolution. So, I use 1920 x 1080 with a scaling factor of 125% (which is recommended by my laptop manufacturer and avoids me having to use ridiculously small text).
The Cubase menu bar works fine with this at startup.
However, after a while Cubase starts to work in a different resolution to the bar. This is for the menu bar only.
I’ve attached a photo of the screen.