I just had same issue start today. I’m in a 2018 Chrysler 300, CarPlay worked fine earlier today and ever since I first bought the car. But today it just will not connect to my I phone. Checked settings and they seem correct. One thing I did notice was I am not getting the Chrysler logo on my screen when I start the car. I know I used to get it, not now, it goes straight to the SiriusXM/radio screen. Before I would get the Chrysler logo then it would display an accept uconnect button. Phone charges, but even in the media mode it doesn’t see my I phone.
Planning on calling the dealer Monday, but if anyone has ideas, I’m open to all. I’ve tried wife’s phone and multiple USB cords with same result. Up to date on apple software too. Very frustrating.