I just got off a chat with GM Support. "This is not a known issue or common problem that has been reported." Please everyone go to the GMC or Chevy website, go to support, and chat with them or send them the issue. They aren't going to fix it unless we all start raising hell about it.
I have the exact same issue. I bought a 2020 AT4 a couple of weeks ago and have this issue every time. I called Apple and they said it's a problem with the vehicle, not the phone. Anyone found a fix yet?