I have a 2011 Cadillac SRX with the same issue. I talked to Apple Support twice, including a next level support agent. I work for a cellular provider and part of my job is tech support, and I had completed literally EVERY step I could think of, and found online and what the agent had me try, if I hadn’t done it yet. Nothing worked. Eventually the agent and I came up with that it was definitely the iOS update and we will have to wait until the next update and hope it is fixed. Meantime, I’m either using my iPad, which is still on an older update, with an USB to USB-C cable, or using the lightning to aux adapter with my phone and they work. Bluetooth works too, but the audio and bass quality sucks compared to with a cable.