When recording notes or editing notes in the midi key editor and the track is record-enabled, the playback randomly drops the pitch of the instrument by about 2 semitones. I noticed this in both Kontakt 5 and Kontakt 6 player, but believe it was also happening with other VST instruments as well. Removing the instrument and re-adding it doesn’t always correct the issue - sometimes I will have to restart Cubase for the issue to resolve itself.
Fresh install of Mac OSX Mohave with 10.0.20 update (just did a fresh install this week)
If the track is not record-enabled, I haven’t yet noticed the issue. Playback stays consistent.