[iOS] Group Header/Footer Repeated for All Items When IsGrouped is True for ObservableCollection in CollectionView

[NafeelaNazhir]

Description

This sub-issue tracks a platform-specific problem on iOS when IsGrouped is set to True and the ItemsSource is set to ObservableCollection. The GroupHeaderTemplate and GroupFooterTemplate are incorrectly applied to every individual item in the collection.
This issue was previously not identifiable on iOS because of #28509 where GroupHeaderTemplate and GroupFooterTemplate were not visible. After fixing this #28509, this issue will occur on iOS also.

Steps to Reproduce

1. Run the attached sample IsGroupedSample.2.zip
2. Select ItemSource= Observablecollection or List , IsGrouped= true, Select GroupHeaderTemplate and GroupFooterTemplate .
3. Observe the behavior of the CollectionView.

Expected Behaviour:

• The GroupHeaderTemplate and GroupFooterTemplate should only be applied when the ItemsSource is a grouped collection.

• When using a flat ObservableCollection, only the individual items should be displayed, without any group headers or footers.

• The GroupHeaderTemplate and GroupFooterTemplate should not be applied to individual items in the ObservableCollection.

Actual Behaviour:

The GroupHeaderTemplate and GroupFooterTemplate are incorrectly applied to each item in the flat ObservableCollection, resulting in multiple headers and footers—one for every item—even though the data is not grouped.

Link to public reproduction project repository

No response

Version with bug

9.0.60 SR6

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

No response

Affected platforms

iOS, macOS

Affected platform versions

No response

Did you find any workaround?

No response

Relevant log output

[similar-issues-ai]

We've found some similar issues:

• [Android] Group Header/Footer Repeated for All Items When IsGrouped is True for ObservableCollection #28827 , similarity score: 88%
• GroupHeaderTemplate and GroupFooterTemplate Not Displaying in CollectionView(CV2) #28509 , similarity score: 86%
• Header/Footer Template and View Synchronization Issue in .NET MAUI CollectionView (CV2) #28504 , similarity score: 82%
• CollectionView Displays Blank UI When Changing IsGrouped and ItemsSourceType #28826 , similarity score: 81%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

Note: You can give me feedback by 👍 or 👎 this comment.

[anandhan-rajagopal]

This issue has been verified in Visual Studio Code (1.99.3) using the inflight/candidate branch. It can be reproduced on iOS for both CV1 and CV2 platforms. The issue was identified after merging this PR. In previous release versions, the templates were rendering as a blank output.