Hi @chris_999
It maybe beneficial to navigate to the iPhone 7 settings related to GPS to check that all options are ticked to give high accuracy results and look at App permissions.
Launch the Settings app and navigate to Privacy and browse for Location Services. You should see the Location Services toggle so by tapping this you should be able to turn on and off GPS on the iPhone 7.
To add below the toggle you will see a list of apps that have access to GPS location. There you can manually turn off GPS permissions for each specific app depending on what you like.
If all settings are as they should be then Try deleting the App from your iPhone and from your iTunes on a Computer and re download it.
If you get stuck then if you have an Apple Store Local the GeniusBar within can run a diagnostic on the iPhone.
Current Phone >
Samsung Galaxy s²³ Ultra 512gb Phantom Black.
