MFMailComposeViewController NavigationBar not conforming to the appearance protocol

Hello,

I'm trying to display

MFMailComposeViewController

if MFMailComposeViewController.canSendMail() {
  let mailComposeViewController = MFMailComposeViewController()
  mailComposeViewController.navigationBar.tintColor = .white
  mailComposeViewController.mailComposeDelegate = self
  mailComposeViewController.setToRecipients(["support@gmail.com"])
  mailComposeViewController.setSubject("Feedback")
  present(mailComposeViewController, animated: true)
} else {
  print("This device is not configured to send email. Please set up an email account.")
}

This is how I set the styles for the navigation bars.

UINavigationBar.appearance().barTintColor = .green
UINavigationBar.appearance().tintColor = .white
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
if #available(iOS 11.0, *) {
  UINavigationBar.appearance().largeTitleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
}

In iOS 12, it shows up without an issue. See here.

For iOS 13, I added the following code for setting the styles.

if #available(iOS 13.0, *) {
      let navigationBarAppearance = UINavigationBarAppearance()
      navigationBarAppearance.configureWithOpaqueBackground()
      navigationBarAppearance.backgroundColor = .green
      navigationBarAppearance.titleTextAttributes = [.foregroundColor: UIColor.white]
      navigationBarAppearance.largeTitleTextAttributes = [.foregroundColor: UIColor.white]

      UINavigationBar.appearance().standardAppearance = navigationBarAppearance
      UINavigationBar.appearance().scrollEdgeAppearance = navigationBarAppearance
}

But when I run on a device (iOS 13.2), the colors don't show up. See here.

Is this an iOS bug? Or am I missing something in the appearance setting?

Thanks!