They’ll presumably be able to take their time to help you out then because I don’t see this pitch change issue using the case mentioned above, nor any others I can think to try, including your steps, on either a Mk1 or Mk2, and even using the DVCO on Track 3 being careful that Track 4 is clear … nor do I see any simple repeatable steps to methodically reproduce the issue from defaults

Plus I seem to have confirmed that the bug (presuming there was one) was indeed fixed some time ago