Incase this helps anyone- I was having the same issue with an avic 8000NEX in a 2011 Dodge nitro.
Carplay would connect, spotify would play, but no call audio, no siri audio, and it appeared my voice wasn't getting to siri judging by the voice line that should have been wavy.
I am using the idatalink Maestro RR with the appropriate HRN-RR-CH1 harness for Chrysler.
My car has the factory upgraded sound system WITH an amp. The instructions for the maestro say to verify this with specific wires absent from the factory harness, however, I HAVE these wires, and following the instructions