DDJ FLX10 Double Time Parts Not Working

I just unboxed and started trying my brand new FLX10 and was excited about the double time parts but it is not working.  i am hitting the shift button and the different stem options and it doesn't move onto the other track, nothing happens except that it activates or de activates the sound in the deck playing.  i made sure i have the updated software etc, nothing seems to work

please help!!  thank you!

Aaron