Accessory not supported by this device

Hi,

I've had a new deck installed in my car for about 1.5 weeks.

I'm having compatibility issues with my 15PM.

It happens both wired and wirelessly, I get the error "Accessory not supported by this device". It used to happen all the time, now it's 50/50. Sometimes it works.

I've removed and added Bluetooth multiple times on phone and deck, I bought a belkin usb-c to usb-a cable today and it seems to fix it but the problem comes back.

I've changed the setting "FaceID and passcode-allow access when locked-accessories."

The car stereo guy reckons it's definitely an issue with the phone not the deck, I'm inclined to believe him since the error states "by this device".

Any advice appreciated.

Accessory not supported by this device
 
 
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