There is a new requirement in Android 10+ devices.
In order for the location tracking to continue working in the background, if the user chooses the "allow while app is open" permission option we need to add this line to the manifest editor:
B4X:
SetServiceAttribute(Tracker, android:foregroundServiceType, "location")
It also requires installing "android sdk platform 29" with B4A Sdk Manager and configuring the path to android.jar under Tools - Configure Paths to android.jar from platform 29.