Update: Installing the latest nVidia drivers v375.70 seems to have fixed the issue.
I had a hunch because whenever I scrolled or moved my mouse the audio would glitch. I disconnected a couple of my USB devices and that didn’t help and next I read up on nVidia and Cubase and found this thread:
After the latest drivers I can scroll smoothly without issues. Recording and playback of that MIDI track with 128 samples buffer has been smooth. I also have Process Lasso running, but I’m not sure if it’s necessary now.
Hope that helps others coming across this thread!