My iPhone has the volume turned down ever time I connect to my 2019 GMC AT4. I had the phone checked and all diagnostics came back fine. You have to manually adjust the volume on your phone when entering or leaving the truck. to avoid missing calls. Spent numerous hours trying to figure this out. It works fine in my wife's Ford Explorer. So, I took it back to the dealer to find it is a know problem and GMC has no updates to fix it. Has anyone experienced this and found a resolution, as I am confident after speaking to GMC that it a program coding issue for them.
