[Bug] Accessibility tags are removed on the detail side when using MasterDetailPage on iPhone with Xamarin.Forms 4.8

[ismith78]

Description

When using a MasterDetailPage the accessibility tags on the detail side appear to be removed when the master view is seen. This can be easily reproduced with the reference MasterDetailPage code at https://docs.microsoft.com/en-us/samples/xamarin/xamarin-forms-samples/navigation-masterdetailpage/ deploying to an iPhone simulator and using the accessibility manager to check the tags.

Steps to Reproduce

1. Download the Xamarin.Forms MastyerDetailPage example from https://docs.microsoft.com/en-us/samples/xamarin/xamarin-forms-samples/navigation-masterdetailpage/
2. Check the version of Xamarin.Forms, my version was using 4.3.0.908675
3. From XCode start Accessibility Inspector
4. Build and deploy to an iPhone simulator
5. Open the menu by tapping on the hamburger icon
6. Check that the accessibility manager can see the hamburger icon on the detail side of the MasterDetailPage
7. Upgrade the version of Xamarin.Forms to the latest 4.8.0.1269
8. Repeat steps 4-6

Expected Behavior

The hamburger icon should still have the accessibility tags present so that it can be tapped and closed when acessibility is enabled.

Actual Behavior

The hamburger icon, and anything on the detail side has all accessibility tags removed. On a real device this also prevents the menu from being dismissed when tapping on the detail side.

Basic Information

• Version with issue: 4.8.0.1269
• Last known good version: 4.5.0.396
• IDE: Visual Studio Mac 8.7.4 (build 38)
• Platform Target Frameworks:
  • iOS: 10.3.4 (iPhone5), 11.4 (iPhone7 simulator), 13.6 (iPhone 11 simulator)
• Nuget Packages: Xamarin.Forms 4.8.0.1269
• Affected Devices: iPhone 5, iPhone 7 (simulator), iPhone 11 (simulator)

Screenshots

Xamarin.Forms 4.8.0.1269 (note that the hamburger icon has no accessibility focus)
Xamarin.Forms 4.3.0.908675 (note the focus on the hamburger)

Reproduction Link

Download the reference MasterDetailPage code from https://docs.microsoft.com/en-us/samples/xamarin/xamarin-forms-samples/navigation-masterdetailpage/
Deploy to iOS simulator and check accessibility tags when the menu is displayed
Deploy to a real device with VoiceOver enabled, then tap to open the menu and then try to dismiss the menu
Upgrade to Xamarin.forms 4.8 and repeat the test

Workaround

[ismith78]

This looks like it was broken in 4.5.0.495 (SR2). When using 4.5.0.396 the accessibility tag for the hamburger is correctly seen when the master view is opened. Once I update to any version of Xamarin Forms above 4.5.0SR1 then the issue is observed.