PRO LINK

I have 2x CDJ 3000 and 1x DJM 900NXS2, which are connected through a switch.  Everything works fine (red light on platter for main player, synced up effects, etc...) expect I can not hear the touch cue in my headphones.  It looks like the touch cue is working fine, I just cant hear the cue music. And I have the cue link button on mixer engaged.  Is there something else I need to do?