Trouble with Traktor Kontrol S5 and pre-cue headphones

Hi,

I’ve been able to map most of the controls on my S5, but some of the key ones - Main Volume, Booth Volume, Cue Mix, Cue Vol - are not detected when MIDI mapping. I’ve confirmed that the controller drivers are fully up to date.

Additionally, I am not able to get my Pre-Cue headphones to work through the controller - that output seems to be invisible to DJay Pro.

I also can’t get the Pre-Cue headphones to work through my Steinberg UR22 audio interface - when I hit ‘Split Output’, it splits the output of my L speaker output from the interface, from the R speaker output, and causes the R speaker to cut out. It’s basically trying to use my R speaker output as the Cue Headphones, and it can’t see the 3rd line (my headphones) connected to the interface.

Any suggestions on how I can get Pre-Cue headphones working? My preferred solution is to work though my audio interface, if possible.