Audio issue with Kemper Head today (10.1.2.47971)

Was playing around with a lap-steel studying a few youtube-lessons when I noticed that my open-d-tuning was way off from the video, it was consistent across several videos. About 1,5 semitones sharp when I had used the tuner on the KPA. Then after about half an hour the audio starts crackling. Switching rigs, and back and forth between modes etc changes nothing. There are no errors reported by the KPA. After reboot everything is back to normal, at least for now. The crackling was like there is a an internal sync problem, and one that also throws the tuner off. Scary. It would be a very unpleasant experience on stage. Ticket filed.

First reply from Kemper suggest sync-problems with a USB-attached computer. I responded that my KPA had a USB-cable attached, but that there had been nothing connected to the other end of the cable.