Getting 0.0 values for latitude and longitude with FusedLocation (but not always)

Question

I need to get latitude and longitude from an RecyclerView adapter. Each item has a camera, which when is clicked, should get and save location. Each item can be clicked on different locations.

I use this Service to get location, but the problem is that it is more the times those values are 0.0 than the times they actually have latitude and longitude values. So, it works, but only sometimes.

Can you help, please?

In MainActivity, I start the Service like this:

private void startLocationService() {
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
            ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("Permission needed.")
                .setCancelable(false)
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
                    }
                });
        AlertDialog alert = builder.create();
        alert.show();
    } else {
        startService(new Intent(this, LocationService.class));
    }
}

And this is the code of the Service:

public class LocationService extends Service {

    private FusedLocationProviderClient fusedLocationClient;
    private LocationCallback locationCallback;
    private LocationRequest locationRequest;

    public static double latitude = 0.0;
    public static double longitude = 0.0;

    @Override
    public void onCreate() {
        super.onCreate();

        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
        locationRequest = LocationRequest.create();
        locationRequest.setInterval(10000);
        locationRequest.setFastestInterval(5000);
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        locationCallback = new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                if (locationResult == null) {
                    return;
                }
                for (Location location : locationResult.getLocations()) {
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
        };

        startLocationUpdates();
    }

    private void startLocationUpdates() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
                ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        fusedLocationClient.requestLocationUpdates(locationRequest, locationCallback, Looper.getMainLooper());
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        fusedLocationClient.removeLocationUpdates(locationCallback);
    }
}

Then, on my adapter, I access those like this:

LocationService.latitude

and

LocationService.longitude

Thank you.

Kind regards.