CarPlay stopped working with IPhone 12.

Hello,

I just got a 2017 Hyundai Elantra about 2 weeks ago. I have an IPhone 12 and the Apple CarPlay was working just fine. Then it stopped working for two days and started working again. I was hoping for the best but of course it stopped again. I brought it to the dealer but they want 100 bucks to even look at it. I’ve restarted my phone, restarted the car, hit the pinhole restart button, bought a new apple usb cable, did a factory setting reset on my phone, and nothing is working. Do you guys have any idea how I can fix this? Or who I can contact?