The CoreLocation module always fails to fetch my phone’s real location accurately, and the location shown by showUserLocation always has a slight deviation.

The code of LocationViewModel.swift

import Foundation
import CoreLocation
import Combine

class LocationViewModel: NSObject, ObservableObject, CLLocationManagerDelegate {
    private let locationManager = CLLocationManager()

    @Published var location: Location?
    @Published var authorizationStatus: CLAuthorizationStatus?
    @Published var errorMessage: String?
    @Published var gpsSignalStatus: String = "Detecting GPS signal..."

    override init() {
        super.init()
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation
        locationManager.allowsBackgroundLocationUpdates = true
        locationManager.pausesLocationUpdatesAutomatically = false
        checkAuthorizationStatus()
    }
    
    func checkAuthorizationStatus() {
        authorizationStatus = locationManager.authorizationStatus
        switch authorizationStatus {
        case .authorizedWhenInUse, .authorizedAlways:
            locationManager.startUpdatingLocation()
            locationManager.startUpdatingHeading()
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization()
        case .denied, .restricted:
            errorMessage = "The authorization of location is limited。Please turn it on in settings"
        default:
            errorMessage = "Unknown location authorization status"
        }
    }

    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        checkAuthorizationStatus()
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        guard let location = locations.last else { return }
        self.location = Location(
            coordinate: location.coordinate,
            altitude: location.altitude,
            speed: location.speed,
            direction: location.course,
            horizontalAccuracy: location.horizontalAccuracy,
            timestamp: location.timestamp
        )
        
        if location.horizontalAccuracy < 0 {
            gpsSignalStatus = "GPS is not avaliable"
        } else if location.horizontalAccuracy > 100 {
            gpsSignalStatus = "GPS signal is weak."
        } else {
            gpsSignalStatus = "GPS signal is great."
        }
    }
    
    func locationManager(_ manager: CLLocationManager, didUpdateHeading newHeading: CLHeading) {
        if var currentLocation = self.location {
            currentLocation.direction = newHeading.trueHeading
            self.location = currentLocation
        }
    }

    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print("Failed to find user's location: (error.localizedDescription)")
    }
}

The code of LocationView.swift

...
struct MapView: View {
    @ObservedObject var viewModel: LocationViewModel
    
    @State var cameraPosition: MapCameraPosition = .automatic
    
    var body: some View {
        ZStack {
            Map(position: $cameraPosition) {
                if let coordinate = viewModel.location?.coordinate {
                    Annotation("MyLocation", coordinate: CLLocationCoordinate2D(latitude: coordinate.latitude, longitude: coordinate.longitude)) {
                        Text("The position which CoreLocation got")
                    }
                    
                }
            }
            .onReceive(viewModel.location.publisher) { location in
                cameraPosition = .region(MKCoordinateRegion(
                    center: location.coordinate,
                    span: MKCoordinateSpan(latitudeDelta: 0.0025, longitudeDelta: 0.0025)
                ))
            }
        }
    }
}
...

The position obtained from CoreLocation has an error of several hundred meters compared to the actual position.

1. Any problem in my code?
2. Is there a way to obtain the right location?