Ok, maybe I'm insane but I spent the last hour going through a Bluetooth HCI snoop log. I found the offending packet. Supposedly my Uconnect Bluetooth is assigning repeat mode 3 and shuffle mode 1. Not sure what those mean or why considering the interface in my car doesn't even act like repeat and shuffle work on Bluetooth and for Android 13 and below, this didn't happen in Poweramp. Now I feel like i should try capturing on my old phone that still runs Android 13 and see if the same packet is coming through.
I also still need to locate and try a non-car Bluetooth audio device to test that.