djay pro cueing help

I purchased a mixtrack pro 3 a few months back, and since i've been dabbling on and off with djing.

Firstly i grabbed a bunch of songs off of bpmsupreme after getting a week free trial, and then messed with serato for a while, then got bored of most of that music. I've decided i don't want to invest into a monthly record pool subscription or buy music currently, nor do i want to play out.

Because of this, i decided on trying out djay pro so i could mess around using my spotify library, and maybe dj some little parties at uni halls and actually be able to take requests.

After setting up my controller however, i've realised the headphone cue buttons aren't working, firstly they don't light up when pressed, and also they don't play any sounds through the headphones

I looked online and apparently there was an issue with how djay pro outputs, basically meaning using two sources isn't possible, i'm not sure if any of you can verify this? If this is the case, what would the solution be?

Did you get Serato DJ licence with your MTP3?

Either your Soundcard is not set up correctly or Midi Mapping is incorrect.