Upgraded to iPhone16 with iOS18. Now Apple CarPlay does not work with my 2019 Kia Niro EV. Tried some workarounds suggested on other panels but no joy. Airplay icon shows up on menu screen but is grayed out.
CarPlay not working using iOS18
I recommend that you take this issue to the Apple Support Community. https://discussions.apple.com/
The Developer Forums are for questions about development on Apple platforms, and this question does not seem to be a development-level issue.