CarPlay & Hearing aids audio routing

Hello-

In brief- I'm trying to figure out audio routing to my hearing aids when I use my new CarPlay radio.

I have iPhone 6 plus iOS 9.3.1

Resound Linx2 hearing aids

Pioneer AppRadio 4 with CarPlay

On my phone I have all the hearing aid audio routing settings set to Automatic

When get in my car I start the car and plug in my phone. Once I plug in the phone, it will log into CarPlay and start playing audio- but it is routed to my hearing aids.

Then I have to got to control center and select digital display- to get it routed to the radio. If I select Pioneer AppRadio- the audio stays routed to my hearing aids.

I have tried waiting until the radio is complete booted up. I have tried plugging in the phone before I start the car.

As write this I'm realizing the only I haven't done is a firmware update on the Radio- but my understanding is that the CarPlay functionality is all through the phone and iOS. I will try a firm ware update tonight when I get home.

Thanks for any help or insights.

-A