I checked a few other of my phones laying around. It depends on what version of Android you have as to what you see.

 

I have a GS7 and it just updated the software today, so everything is up to date.

 

Delete the bluetooth connections on truck and phone, crank the volume up to max on the phone and re-pair.

When pairing, there are times where if the volume is low, it can affect the vehicles volume. Also when an upgrade happens it can affect it. Just had this happen with my iphone 6s running a beta iOS. I have a BT speaker and went to play music, and could barely hear it. Deleted, re-paired and it is back to normal.

 

Guys,

Wondering if it's a phone model issue. When I had my iPhone 7, this SYNC/Volume issue was the bane of my existence, but when my phone upgrade came due, and I changed to an iPhoneXS, the issue completely went away. No truck SYNC updates, etc. I unfortunately don't have the 7 anymore to test and see if it would still do it. But just letting you all know what seemed to be the more expensive fix.

 

It’s Waze for sure. I just now tested it. Prompt volume came up as it has, as soon as I deleted it off my phone I got my volume control back. Reinstalled it and I lost my volume control.

Edit: iPhone 11 Pro Max running 13.4.1

 

I had been experiencing this issue with my Apple CarPlay and Waze. I was able to get this resolved today by doing a module reset. Turn your truck on, turn on the AM or FM radio, press and hold the radio power button and the "next song" button for 5 seconds. The screen will go dark, release the buttons, and then the SYNC will reset. I was able to have full audio volume control once this was completed. You won't lose any settings or saved presets.