Cue Channel playing through Master Mix using Numark Platinum controller

I am new to DJing and bought my Numark Mixtrack platinum a couple of days ago. I am using DJ Pro 2 and my Cue channel is playing through my master mix.

I’m under the impression that when the cue button is off the music is supposed to play through the main speakers and the headphones, but when it is on, it is only suppose to play in the headphones. I have my speakers hooked up to Output 1 and when the cue button is off it works as normal, but when it is on, you can also hear it through the speakers even though it is lower volume than what is supposed to playing live. Is this supposed to be the case or is there a problem with my setup?