[Bug] [iOS] SelectedItems custom image not displaying in iOS for CollectionView until tapped

[adolfo1981]

Description

Followed this solution to display checkbox images (check/uncheck) for CollectionView Items. Checked checkboxes do not show when loading my page with pre-selected items in iOS, but works fine in Android

Steps to Reproduce

1. Create a Custom ContentView defining a CustomImageSource BindableProperty to define image as shown in article linked above
2. Refer to the Custom ContentView in the CollectionView.DataTemplate

        <CollectionView.ItemTemplate>
            <DataTemplate>
                <local:CustomView/>
            </DataTemplate>
        </CollectionView.ItemTemplate>

3. Define a ResourceDictionary to set the image sources for checked and unchecked checkbox images based on state as shown in reproduction GitHub link.
4. Load CollectionView ItemsSource in the ViewModel and load SelectedItems for the CollectionView. See in reproduction GitHub link

Expected Behavior

Pre-selected CollectionView items show checked checkbox images.

Actual Behavior

In iOS CollectionViews appear with default blank checkboxes until CollectionViews are tapped. That's when selection checkbox images are displayed

Basic Information

• Platform Target Frameworks: Xamarin.Forms v 5.0.0.2012
• Affected Devices: iPhone 6 to 13

Environment

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Microsoft Visual Studio Professional 2019
Version 16.10.4
VisualStudio.16.Release/16.10.4+31515.178
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Build Logs

Screenshots

Reproduction Link

https://github.com/adolfo1981/MultiCollectionViewTest

Workaround

I tried this workaround using a CollectionView Behavior and seems to be working: #9511 (comment)

[adolfo1981]

This bug seems to be related to this bug: #6967

[adolfo1981]

Also similar to #9511