
I am having the same problem. After playing with rekordbox for 30-45 minutes with track separation of one of the decks starts misbehaving. When choosing one or more stems the playback of the track is heavly distorted and not playable. Not using the stems the track sounds normal. when loading a new track the behaviour of that deck stays the same. The other deck and stems works fine. The only way to repair is restarting rekordbox. Which offcourse is not something you want to do when performing for public.