Hi Cuz,
Often when people have problem getting a PFL or Cue signal through their headphones, it means their routing is set incorrectly. Depending on you controller and software there is only one correct way to set that in the software. For my DDJ-SX in Mixvibes Cross for example it’s set two simple stereo I think. Meaning deck A goes to channel A and deck B goes to channel B. From there I can cue listen to both channels by pressing the cue button on each channel. Some controllers work differently and need the pfl or cue function to work in the DJ software. Here you would set the routing to send the master volume from the DJ software to the master output on the controller and the cue signal to the headphone output of the controller.
I don’t know what combination/setting you need with the NV and VDJ as I haven’t seen the NV up-close yet and I am not familiar with the audio settings in VDJ.
But, since we have a zillion readers, I am sure one can come up with the exact settings for you.