Navigation Bar disappearing when tapping done from youtube embedded player (iOS)

Question

I have a Youtube embedded player in one of the views of my app. If I exit playback in landscape mode, the navigation bar shrinks to half its size throughout the app. The app is set to portrait mode by default.

Here is the shrunken navigation bar

The navigation bar, however remains fine if I tap done in portrait. How can I solve this problem?

EDIT: The playerView code:

    @IBOutlet weak var playerView: YTPlayerView!

override func viewDidLoad() {
    super.viewDidLoad()

    print(passVideoId)
    playerView.loadWithVideoId(passVideoId)

}

passVideoId is the video id passed on from the previous view.