IOS device are not returning accurate location Flutter Geolocator package

Question

one of the functionality of the app is to

1. scan a qr code ->

2. fetch user current location ->

3. check that location matches with a geofence or with in geofence ->

4. if so complete desginated task or else show error to user saying u r offsite

in the ios devices frequently this offsite issue is thrown even tho they are inside the geofence not in android

how can i resolve and make IOS also smooth and android ?

do i have to make any precise change for IOS?

ill add my logic down below

  void _verifyGeoScanWithLatLong(String scanResult) async {
    if (null == _userInfo.userInfoDetails!.site!.geofence ||
        _userInfo.userInfoDetails!.site!.geofence!.trim().isEmpty) {
      AppSnackBar.show('Site is not properly configured',
          icon: AppSnackBarIcon.SUCCESS);
      return;
    }

   _appProgressBar.showProgress();

//here fetches the user current location
   final Position position = await Geolocator.getCurrentPosition(
        desiredAccuracy: LocationAccuracy.high);
// add that to geoPoints by spiliting that line of string 
    List<GeoPoint> fencingList =
        getPathFromPoly(_userInfo.userInfoDetails!.site!.geofence!);
// checks weather within fence or not
    bool isWithinFencing = isPointInPolygon(
      GeoPoint(latitude: position.latitude, longitude: position.longitude),
      fencingList,
    );

    _appProgressBar.hideProgress();

    if (isWithinFencing) {
      _verifyNeoScanAndSubmitLocation(scanResult, position);
    } else {
      ConfirmationDialog.show(
        context,
        title: 'Scan Failed',
        description: 'You are off Site',
        positiveButtonText: 'Scan More',
        negativeButtonText: 'Done',
        isDismissible: false,
        onPositiveClick: () {
          Future.delayed(Duration.zero, () async {
            result = null;
            await controller?.resumeCamera();
          });
        },
        onNegativeClick: () {
          Future.delayed(Duration.zero, () {
            locator<NavigationService>().back();
          });
        },
      );
    }
  }

adding the method to parse string lat long to geopoints

List<GeoPoint> getPathFromPoly(String polygon) {
  List<GeoPoint> geoList = [];

  var points = polygon.split('),(');
  points[0] = points[0].replaceAll('(', '');
  final length = points.length - 1;
  points[length] = points[length].replaceAll(')', '');

  for (int i = 0; i < points.length; i++) {
    var latLng = points[i].split(',');
    GeoPoint geoPoint = GeoPoint(
        latitude: double.parse(latLng[0]), longitude: double.parse(latLng[1]));
    geoList.add(geoPoint);
  }

  return geoList;
}

adding the method to check weather this geopoint is inside the geofence

bool isPointInPolygon(GeoPoint tap, List<GeoPoint> vertices) {
  var intersectCount = 0;
  for (int i = 0; i < vertices.length - 1; i++) {
    if (_rayCastIntersect(tap, vertices[i], vertices[i + 1])) {
      intersectCount++;
    }
  }
  return ((intersectCount % 2) == 1); // odd = inside, even = outside;
}

bool _rayCastIntersect(GeoPoint tap, GeoPoint vertA, GeoPoint vertB) {
  final aY = vertA.latitude;
  final bY = vertB.latitude;
  final aX = vertA.longitude;
  final bX = vertB.longitude;
  final pY = tap.latitude;
  final pX = tap.longitude;

  if (aY > pY && bY > pY || aY < pY && bY < pY || aX < pX && bX < pX) {
    return false;
    // a and b can't both be above or below pt.y, and a or
    // b must be east of pt.x
  }
  final m = (aY - bY) / (aX - bX); // Rise over run
  final bee = -aX * m + aY; // y = mx + b
  final x = (pY - bee) / m; // algebra is neat!
  return x > pX;
}

these are the logics i used do i have to use any other logic or what more can i do to solve this frequent event of location not being precise on ios

note: in the device which had issue location precise is enabled as well as location permission to app is enabled and kept as always.

i tried restarting phone to check will it fetch latest location

updated geolocator package