iPhone 15 Pro
iOS 17.2.1
I have a similar problem on my iPhone 15 Pro.
Bluetooth voice call quality is poor and the connection drops nine times out of ten at around 40 seconds before reconnecting and being completely stable.
Spoken to numerous advisors and reset network settings, all settings, changed my phone name etc: STILL DOESN'T WORK.
After remotely checking my phone’s hardware and none of the resets having worked, their conclusion is that it’s the car manufacturers problem as the software in the car must need updated to support newer phones.
Key Points:
1) Connection is stable once it reconnects during a call after 40 seconds.
2) My partners iPhone 14 running 17.2.1 connects.
3) My old XR running 17 connects.
4) Calls via AirPods completely fine.
4) Support recommendations don’t make any difference bar needing me to redo FaceID, redo wifi and Bluetooth connections and restore all of my phone preferences one at a time.
Not happy.