Cubase Artist 8.5 Random transpose in MIDI

Hi all,
New to this board. Have been using Cubase Artist 8.0 on my Windows 7 machine for 1 year now, and several months into it (about 8 months ago) upgraded to Artist 8.5. My AD converter and IO is a 6i6 focusrite scarlett. have been running into a really frustrating problem recently while writing tracks… at completely random times, a MIDI track I have written for a VST will randomly all shift up one semitone. The entire thing. It sounds like crap and it just sucks.

I notice that there are Ableton and Logic forums dealing with this issue, that seem to point to there being some sort of MIDI communication problem. Indeed if I click on “Reset” in the MIDI menu in Cubase, it temporarily brings the pitches back to the way I originally intended them to sound, and sometimes double-clicking on the keyboard editor directly in the track works, but it soon shofts back up again. I really don’t know what to do, besides reinstalling my drivers and Cubase, but figured I would check here if anyone had any ideas.

Thanks for any help.