Thank you for your post. There could be a number of factors that would be causing an issue.
Here is a list of things you can check when you have poor GPS accuracy:
1. Ensure that you are using GPS Fixtures and not Network Fixtures. Network Fixtures are based on your cellphone’s connection to the nearest cell phone tower. A network connection for location accuracy is not as consistent, reliable, or precise as a GPS fixture. The easiest way to do this is to turn off your mobile network while using the app.
There is also a setting that can fix this:
Android: Avenza Maps > Settings > GPS > Only Use Satellite Fixes > Turn On
2. You can check your GPS Track Settings and apply the settings that apply to the environment you are in. For example, if you are experiencing inaccurate GPS readings while you are in an open field, you can change to Keep All Fixes and it will give you more readings so it will be more accurate for Time and Distance. Horizontal accuracy is a bit trickier.
3. Make sure that Battery Saver is turned off, when the battery saver is turned on, it will diminish the performance of the GPS. Ensure that you don’t have it set to Optimized because that can cause issues with GPS and Bluetooth connectivity. With the release of Android 9 and 10 there are built-in low-power integrations that can cause that issue when it goes to sleep many functions are halted or put on reduced performance to conserve battery life. This includes GPS function since it isn’t an essential service to be running while the screen is turned off.
Additionally, if you continue to have issues, could you please contact us at firstname.lastname@example.org. It will allow me to get some more information to diagnose your issue.