Hi rabmozzer,
Thanks for using Apple Support Communities. The first thing you'll want to check here is that the iOS is updated on your device. Go to Settings > General > Software Update and if an update is available, please install it.
You can also see how to turn off Maps by having Siri to stop navigating or end route. Check this out: Get turn-by-turn directions with CarPlay
"Follow turn-by-turn directions
As CarPlay follows your progress, it speaks turn-by-turn directions to your destination.
Do any of the following at any time during your trip:
- Add a stop to your driving directions: Select the ETA display at the bottom left, select Add Stop, then choose a destination or use Siri to search for one.
- End directions at any time: Say something to Siri like “Stop navigating,” or select the estimated time of arrival (ETA) display at the bottom left, then choose End Route.
- Mute turn-by-turn directions: Tap
, then choose 
to mute all directions. - Mute turn-by-turn directions, except for alerts and hazards: Tap , then choose
. - Make a quick detour: Say something to Siri like “Find a gas station.” Or select the ETA display, select Search, select a suggested service, then choose a destination.
- Share your ETA: Select the ETA display at the bottom left, select Share ETA, then choose one or more suggested contacts.
- People using devices with iOS 13.1, iPadOS 13.1, or later receive a Maps notification with your ETA, and they can track your progress in Maps. People using devices with earlier versions receive the notification through iMessage. People using other mobile devices receive an SMS message. (Standard carrier data and text rates may apply.)
- To stop sending ETA information, select Sharing ETA at the bottom of the CarPlay screen, then choose a contact."
You can also turn off cellular data for specific apps using this article as a guide: Use cellular data on your iPhone or iPad - Apple Support
Cheers!
