I’m getting periodic framerate drops in Cubase 10 on my new 1440p 144Hz screen (applying the latest update didn’t help). It’s like the mouse framerate drops to about 20fps. This only occurs in Cubase, and only on my main screen. It doesn’t happen on my secondary 60Hz screen which is used for the mixer, and it didn’t happen even when that screen used to be the main screen. The framerate drops for a few seconds, then goes back up, then down again, and so on. Sometimes the screen flickers a bit when it dips. Disabling the Steinberg Power Scheme makes it worse - it makes the framerate stay low almost all of the time. It doesn’t seem to happen in an empty project, but the project I’m testing now is only at 10% CPU usage and under 50% RAM.
PC is an i7 8700 with 64 gigs of RAM running Windows 10. GPU is a GTX 1060. Cubase is running off a Black Caviar HDD (with some libraries running off an SSD). Main screen is an AOC AGON AG271QX which works perfectly fine outside Cubase. Switching to 60Hz doesn’t fix it.