After my app has been backgrounded for a while and I foreground the app CLLocationManager will fire and I will get a CLError.denied error even after the app has .authorizedWhenInUse permission.

    init() {
        locationManager = CLLocationManager()
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters        
    }

    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        if status == .authorizedWhenInUse || status == .authorizedAlways {
            locationManager.startUpdatingLocation()
        } else {
            locationManager.requestWhenInUseAuthorization()
        }
    }

func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        guard let clErr = error as? CLError else {
            return
        }
        
        switch clErr.code {
        case CLError.denied:
            showDeniedLocationError()
            break
        default:
            break
        }
    }

For example in the above didFailWithError the CLError.denied case will get hit if the app was backgrounded for a reasonable amount of time EVEN THOUGH it definitely has permission to get your location. This problem only seems to happen when the app was backgrounded for a while and you foreground the app to continue using it. The app will immediately hit CLError.denied and the error will be shown.

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        if let location = manager.location {
            locationManager.stopUpdatingLocation()
            // update the location
        }
}

Should I even be calling locationManager.stopUpdatingLocation() in didUpdateLocations?

When the app is foregrounded do I need to call locationManager.startUpdatingLocation() every time to try and get around this problem?