I have the same troubles With the sound. In both cars apple car play isn’t working. BMW CarPlay is wireless and the Kia Car Play is wired. I can connect it, but everytime when I want to listen to music or something else the sound comes from my phone instead of my car speakers. I can control everything via CarPlay but the sound is just coming from my phone…connect and disconnect isn’t helping. Restarting my phone isnt fixing the problem too