[Bug] A wrong item is highlighted in the Shell menu on UWP

[holecekp]

Description

If you set the manually which item should be selected in the Shell menu, the UWP version behaves really weirdly. Usually it works well. But sometimes it opens the correct page but it highlight a wrong item in the shell menu as selected. It will be more clear if you look at the screenshot or if you try the repro project.

I am setting the page that should be opened in the Shell constructor in the repro project:

        public AppShell()
        {
           // ...
           CurrentItem = flyoutPage7;
        }

In reality, my application remembers the currently opened page when the application is closed, and tries to open the same page when the application is launched again. However, for the repro project, I am just opening Page 7 for simplicity. The problem depends on the page selected. Selecting Page 1 works (and correct item is highlighted in the menu) while selecting Page 7 and a few others does not work.

Steps to Reproduce

1. Download the repro project and run it. It should open "Page 7" on startup.
2. The page 7 is opened. But if you open the shell menu, page 3 is highlighted as opened instead.

Expected Behavior

Page 7 should be opened in the window. If the user opens the shell menu, Page 7 should be highlighted as opened (there should be a blue line next to Page 7 item.

Actual Behavior

Page 7 is opened in the window. However, if the user opens the shell menu, Page 3 is highlighted as opened (there is a blue line next to it).

Basic Information

• Version with issue: all 5.0 versions are affected including the latest one
• Last known good version: 4.8.0.1687
• Platform Target Frameworks:
  • UWP: 1903
• NuGet Packages: Latest Xamarin.Forms, Essentials and AppCenter.Crashes

Environment

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Microsoft Visual Studio Community 2019
Version 16.9.4
VisualStudio.16.Release/16.9.4+31205.134
Microsoft .NET Framework
Version 4.8.04084

Installed Version: Community

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Screenshots

Page 7 is opened (text on the right-hand side) but Page 3 is highlighted in the Shell menu (on the left-hand side)

Reproduction Link

XamarinRepro-BadShellSelectionInUwp.zip

[rachelkang]

Hi, @holecekp - thanks for sharing! Confirming I'm able to repro the issue
If possible, would you be able to share a sample of the working version on the older version of XF? I tried running your solution on an older version but unfortunately had some trouble building

[holecekp]

@rachelkang It should be suffitient to downgrade Xamarin.Forms Nuget to 4.8, clean the solution and delete all obj and bin folders in it. The last step is important. Cleaning the solution probabably does not clean everything, and I could also see a change only after I had deleted obj and bin folders.