Description

1. IsGrouped / ItemsSource update at runtime does not update CV to grouped mode;
2. Changing grid layout columns count at runtime is dramatically slow - up to minutes. It requires ~10-15ms when CollectionViewHandler1 is in use.

Steps to Reproduce

1. Start the repro app, tap "Ungrouped ColView" and "Grouped CollView" buttons several times, note - group headers appeared when needed;
2. Switch beetwen 4 and 6 columns mode several times, note - it requires ~10-15ms only to CV update on each switch;
3. Uncomment CollectionViewHandler2 registration at MauiProgram.cs and rerun the app;
4. Repeat step 1, note - CV does not updated to group mode on ItemsSource and IsGrouped props change at runtime (but it start work once columns count changed);
5. Repeat step 2, note - it requires more and more time to switch columns count, each next switch requires more time - 0.9s, 1.5s, 3.5s, 6.2s, 14.5s, 25.4s, 61.7s(!) and so on at the my dev environment.

Link to public reproduction project repository

https://github.com/alexpetin/TestCollViewPerf

Version with bug

9.0.90 SR9

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

Any version

Did you find any workaround?

No.

Relevant log output