CLLocationManager is slow getting location, Swift
From the documentation of requestLocation():
This method returns immediately. Calling it causes the location manager to obtain a location fix (which may take several seconds) and call the delegate’s locationManager(_:didUpdateLocations:) method with the result.
Source
So basically, everything is fine with your code, it's just how the framework is built.
When initializing your location manager, add startUpdatingLocation():
let manager = CLLocationManager()
manager.delegate = self
manager.requestWhenInUseAuthorization()
manager.requestLocation()
manager.startUpdatingLocation()
Without startUpdatingLocation() geo-location takes about 5 seconds, with it, the request executes nearly immediately.
Try setting the accuracy and use locationManager.startUpdatingLocation(). I do that, and get answer within a second (on the device).