Make sure the location services for the app is set to "always'. If it is not set to always, when the app is closed the GPS services are not working.
This is what you need to do to set the app to always.
To Set the Location services to always:
- Open Settings
- Scroll down to Privacy
- Tap Location Services
- Scroll down to the GM Driver app
- Tap it and make sure it is set to Always
Please let me know if the app was already set to Always.