Headphone cue & fader controls DNMC6000MK2

New MK2 controller can’t get headphone cue to work. If a song is playing on deck 1 & I press cue to turn off headphone I get no response. Push deck 2 headphone cue & output level decreases. I turn down fader and no response. Push cue for deck 1 & volume jumps to max. So far had this problem on 2 brand new controllers. Waiting on 3rd one to be delivered. Working with tech support on this issue so far unsuccessfully. Using windows 7 & have same problem with VDJ7 & Serato lite software. Can’t help but think there is an easy fix but not finding it . Any ideas?