Camera view of UIImagePickerController frozen when navigating back to it

In the delegate of UIImagePickerController when an image is taken with the camera, another view is pushed onto the navigation stack:

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    picker.pushViewController(otherViewController, animated: true)
}

In the otherViewController the navigation bar is made visible:

override func viewDidLoad() {
    super.viewDidLoad()
    navigationController?.setNavigationBarHidden(false, animated: false) 
}

When the < Back button in the navigation bar is tapped, the navigation bar becomes invisible again, the camera view appears, but the camera image is frozen and tapping the bottom bar buttons has no effect.

Why is that?