The code that works fine on iOS10 (Swift 3) not working on iOS11 Beta (Swift 4 / XCode 9.0 beta)
Setting the image as navigation bar title and adjusting its vertical position:
self.navigationItem.titleView = UIImageView(image: UIImage(named: "some_image"))
self.navigationController?.navigationBar.setTitleVerticalPositionAdjustment(-4.0, for: .default)
self.title = "Some title"
It was an iOS 11 beta SDK bug.
I can confirm that the issue has been resolved in the latest iOS 11 beta 4 (15A5327g) release.