Why does Apple Music switch to Mono in CarPlay?

Hi same thing happened to me, turn off vocal shortcuts in accessibility.

It sounds like a potential iOS 18 or CarPlay glitch. Try restarting both your iPhone and car’s infotainment system. Also, check your audio balance settings in the car and phone. If the issue persists, it could be a software bug—report it to Apple and keep an eye out for updates.

I thought the vocal shortcuts was a cool thing to setup. However it caused my CarPlay audio to sound horrible (mono). I drove myself nuts trying to determine the cause (cables, dirt in lightning port, radio firmware) but nothing helped. Disabled vocal shortcuts and now the CarPlay audio is back to normal again. I suppose this is a bug with iOS 18 (Currently on 18.0.1)

Thanks to the one who published this.

@Aaasvin this fixed it for me and thank you for posting it up. I searched everywhere on the interwebs and this was the only thing that fixed it for me. Hopefully 18.1 will allow me to turn this back on.

Thanks heaps Aaasvin. This fix worked for me and has made carplay usable and stereo sound. Appreciate it !

That fixed my issue. Thanks for the advice