iphone iPhone is continually lowered when connect to GMC

[TRyan8]

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.  

[OnTheReel]

Yup. Thought the newest update fixed it but it did it again today. Turns my iPhone X down to two bars of volume. Very common known issue. Just waiting for a fix.

[TRyan8]

Sad, as I spoke to GMC support today and they do not have a report of this issue.   I now have a case number.  If you have the same issue make sure the dealer or customer support/OnStar have a open case. 

[eric8610]

I had the same problem. Go to settings/sounds and haptics / then turn off change with buttons. It eliminated the low volume when you exit the truck. 

[TRyan8]

I tried this and it did not work.    The Sales Manager also tried it on his iphone and the volume continued to be lowered.   I did see where someone elses on the internet had said to turn off the "change with buttons option".  Thanks for your feedback and trying to help us out.