Multiple issues with CarPlay and it all started with iOS18

I have a 2019 Acura RDX with a wired USB connection using the correct iPhone 15Pro USB-C to USB data transfer cable. I have a 2021 Corvette with both wired and Bluetooth available. The issues are in both cars so the problem is the iPhone, not the cars. "Hey Siri, take me to XXX" "I'm sorry, something went wrong" and I get the whirling ball. or I get, "I'm sorry, I can't connect to the server right now." Sometimes I'll be following the Apple Maps and the graphics will disappear and all I get is a blue/white checkerboard. I've turned Bluetooth on/off, "Forget" on both the cars and the iPhone and re-paired to both cars. In early April 2025, there was an update to iOS 18.4. For two days I said, hallelujah...iMessages started saying "Do you want to reply?" when I got a message. Then...poof...gone. No more "...reply?" It seems that every update, Apple screws up something. I think that they could screw up a two car funeral, too. My mobile carrier is T-Mobile. In my hometown, full scale all over town