I switched my project over to new beta versions of iOS 10 and XCode 8. In all three areas of my app where I use:
imageView.layer.cornerRadius = imageView.fra
It might be a layout issue. Setting clipToBounds to false would show the image even if its size is zero. Can you print the frame of your images?
If you set the cornerRadius and clipToBounds properties in viewDidLoad, try doing it in viewDidLayoutSubviews().
You could also try to call self.view.layoutIfNeeded().