Xamarin.forms: Orientation mode PortraitUpsideDown is ignored in iOS

Description

It seems the orientation mode PortraitUpsideDown doesn't work in iOS and is ignored. The other orientations are okay.

Steps to Reproduce

1. Create new Xamarin.Forms + iOS project
2. Add "UIInterfaceOrientationPortraitUpsideDown" to UISupportedInterfaceOrientations in info.plist file.
3. Start app and turn the phone upside down

Expected Behavior

App changes to PortraitUpsideDown

Actual Behavior

App is still in the normal Portrait mode

Basic Information

• Version with issue: Xamarin.Forms 3.0, 2.5 and 2.4
• Last known good version: Probably versions before 2.4
• IDE: Visual Studio 2017
• Platform Target Frameworks:
  
  
  
  • iOS: 11.3
  
  
  • Android:
  
  
  • UWP:
  
  
• Android Support Library Version:
• Nuget Packages: This bug affects "Plugin.DeviceOrientation", but it also occurs without it
• Affected Devices: iPhone 8, real device and simulator

Screenshots

Reproduction Link