OnPlatform does not work in Header of CollectionView

[suugbut]

Description

The following works.

<CollectionView.ItemTemplate>
    <OnPlatform x:TypeArguments="DataTemplate">
        <On Platform="Android">
            <DataTemplate>
                <Label Text="{Binding .}" />
            </DataTemplate>
        </On>
        <On Platform="WinUI">
            <DataTemplate>
                <Label Text="{Binding .}" BackgroundColor="Red" />
            </DataTemplate>
        </On>
    </OnPlatform>
</CollectionView.ItemTemplate>

However the following does NOT work on both Windows and Android.

<CollectionView.Header>
     <OnPlatform x:TypeArguments="View">
             <On Platform="Android">
                 <Label Text="Android" />
             </On>
             <On Platform="WinUI">
                 <Label Text="WinUI" />
             </On>
     </OnPlatform>
</CollectionView.Header>

Steps to Reproduce

1. Create a project from the default MAUI template.
2. Use the following for the XAML of MainPage. Remove the unnecessary code in the default MainPage.cs.

   <ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
            xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
            x:Class="Bug.MainPage">
   <CollectionView>
       <CollectionView.ItemsSource>
           <x:Array Type="{x:Type x:String}">
               <x:String>A</x:String>
               <x:String>B</x:String>
           </x:Array>
       </CollectionView.ItemsSource>
       <CollectionView.Header>
           <OnPlatform x:TypeArguments="View">
               <On Platform="Android">
                   <Label Text="Android" />
               </On>
               <On Platform="WinUI">
                   <Label Text="WinUI" />
               </On>
           </OnPlatform>
       </CollectionView.Header>
   </CollectionView>
   </ContentPage>

Link to public reproduction project repository

No response

Version with bug

9.0.0-rc.1.24453.9

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

Android, Windows, I was not able test on other platforms

Affected platform versions

No response

Did you find any workaround?

No.

Relevant log output

No response

[Zhanglirong-Winnie]

This issue has been verified using Visual Studio 17.12.0 Preview 2.1(9.0.0-rc.1.24453.9 & 8.0.91 & 8.0.82). Can repro this issue on windows and android platforms.