Streaming from Iphone 6s - no sound from Lightning port, using adaptor


I am trying to stream Pandora from an iPhone 6s, via the Lightning port, into a DAC.

I thought it would be a pretty simple procees: Plug the Apple 3 Adaptor into the Lightning port, then a USB A into the adaptor and the USB B into the DAC.

However, when I do I still only get sound coming out of the 6S speaker(s) 

(When using the headphone and RCA's it silences the speaker, and streams to the preamp with no problem.

I am unable to find anything in Settings that directs the audio to the Lightning port, specifically.

Any help, counsel, hints, etc. would be greatly appreciated. 

Thanks, as always.

anubis

WORKED !!
I did the update and reboot, and when I plugged in the lightning adaptor cable - REALLY pushed it in hard, and that seemed to do the trick …

Thank you sincerely, appreciate the help with these basics ….

If you do not get any warning when you plug in the Lightning cable, you should have sound, but make certain you turn up the volume control.

Update to the latest version of iOS.

re-boot your phone. 
Does this work?