Problems in pre cueing on mac in djay Pro

I bought a split cable for mini jack 3,5 mm port in my mac . I plugged it in and want to pre cue , so I set preferances options like in the photo

and when I click on pre cueing icon to preview song in my headphones while the main is playing i one side of headphones i can hear main song like in the speakers and in the other to
( but quiter like in the background ) and when i click pre cue i can hear preview song i one ear an both preview and main in other . How can I solve that problem to have on sound in speaker and antoher ( after clicking cue icon ) in BOTH sides of headphones .

same problem going on here.
works with my android though.