iPhone 6 no longer sends audio to Alpine CDA-105 in car after updating to iOS 10.2

I have an older Apline CDA-105 head unit in my car. Originally intended to play and control iPods, it's always worked with my iPhones (4 and now 6) via USB and whatever connection the phone supports (ie currently thunderbolt into usb).

Any app that sent audio and also the music app would feed the head unit as long as the it was set to iPod / usb input. Everything was fine until last week after I updated to 10.2. When I plug in the phone and play audio through an app or music, it no longer feeds to the head unit - it just says "No Song" on the head unit itself (previously it would list the track or title of stream).

I can verify the phone is connected as the head unit will says "No usb device" if the connection isn't there. I can also verify music is audio is playing by toggling it on the phone, just no feed to the unit.

Any thoughts or ideas as to why?