I asked that question when I first got my KN7000 almost two years ago. After much discussion, it was decided that it occurs 1.When an expression pedal is used. 2. When the APC slider is not on 127 and a saved. Consequently,a lower volume is produced. I think that is mainly the crux of it. No bugs were ever found,and I disconnected the expression pedal and it fixed my problem.

Bernie