CarPlay Sony AVX-100AX iOS 11 Audio Problem - no sound in Siri/Phone/Maps; Music etc plays fine

Just installed an AVX-AX100 in my 2016 Jeep Wrangler. Uses the PAC-AUDIO RadioPro4 (RP4-CHY11) for CAN-BUS/Steering Wheel Control interface.

I am on an iPhone 6s on iOS 11.1b3. The same symptoms are happening on a different iPhone on iOS 11.0.3. Sony AVX-AX100 is on current firmware 1.0.2.0.6

All in all everything works I can play Pandora, TuneIn through CarPlay screen and other audio on the phone and they will play though the car audio system, but I have no audio in the Phone app, Maps and Siri.(let's call these "Core apps" for CarPlay)

Phone: Called party can hear me fine, I cannot hear the caller. I can turn the "Speaker" function on on the iPhone and then hear them through the iPhone's speaker, but not through the car audio system.

Maps: Navigation works fine, but no voice directions can be heard.

Siri: The microphone works - Siri responds to "Hey Siri" and does what she is told, but there is no audio feedback that can be heard.

Disconnecting the USB cable and using Bluetooth has similar issues.

I noticed that apps other than the Core apps have the option to select for CarPlay or iPhone for audio output.

It seems to me that the issue is that available audio output is not advertised or processed correctly for the Core apps. Specifically, somehow the "hands-free" profile may not be advertised correctly on either CarPlay or Bluetooth.

Troubleshooting steps taken so far:

- Switch Lightning cable to original Apple: no change

- Restarted iPhone and AVX-AX100: no change

- Reset AVX-AX100 to factory settings: no change

- switched Siri "Voice Feedback" Settings from Always to Control with Ring Switch: now I get the Siri chime, but no other audio feedback.

- Checked all audio volumes and settings: no change

Since my phone on iOS 11 worked with CarPlay on another car (a rental with Sync3) I would think this might be a Sony issue.

Any suggestions are appreciated.