I've had my 2019 Dodge 1500 for a little over half a year now. The Apple CarPlay has never worked with my phone. My buddy plugs his phone in and it works fine. I just rented a car and plugged my phone in to the Toyota rental, to my surprise Apple CarPlay worked perfectly. I have tried every combo on this site and still I get nothing. Every once and awhile it will give me a message about a "connection error" but the phone still charges through the cord.
More than likely, it's uConnect and not the phone or cable. I've had the same issue, and last month while at the dealer for the airbag recall, they updated the software and voila. No more issues with CarPlay (it used to never connect and when it did, it would randomly disconnect).
uConnect is pretty lame in this regard. The service advisor showed me the uConnect matrix on the dealer computer, which shows what phones are supported (depending on model & carrier BTW), and for my phone (XS Max) the latest iOSs officially supported are 12.0.1 & 12.1.2 (and this varies by carrier). 12.1 is several months old. Doesn't mean that it will not work, but it shows you how behind they are.
He showed me the same matrix, this time fo his phone (iPhone 6s / Tmobile), and there was no supported iOS for that combination according to uConnnect. Again, does not mean that it will not work, but still pretty bizarre, as that's a four year-old phone that tons of people still carry around.
Tip, test with this as I had this issue and it was a workaround for me: Disconnect your phone from bluetooth,
then plug your phone in.
For me this would allow CarPlay to work. If BT was connected, it would not.
Here's a screenshot of the XS Max:
