A workaround for the issue is to use RadObservableCollection as a source collection. Before the items are added to it, call the its SuspendNotifications method. Respectively, after that call the ResumeNotifications one. 

Another approach would be to populate the items through the AddRange method of the collection.

1.   Run the sample application.

2.   Scroll to the last item.

3.   Begin to resize the window. The direction is irrelevant. Only the horizontal scrollbar needs to be visible.

4.   Observe that in the beginning of the resizing, the scrollbar auto scrolls upwards a little and the last item is half hidden.

The CellUnloaded event of RadGridView is not invoked consistent compared to CellLoaded. For example, when you scroll up and down, the CellLoaded event is invoked for each new cell that appears in the view port. However, CellUnloaded is not invoked for cells going outside of the viewport.

Empty cells appear when the RadGridView contains many cells in the viewport and the view gets resized.

To work this around you can extract and modify the ControlTemplate of GridViewCell, in order to set the MinHeight property of the "PART_ContentPresenter" element to a number close to the RowHeight of the RadGridView control.

The cell content gets clipped when the width of the previous column changes at runtime. This happens in the Windows11 and Office2019 themes (possibly in others) and only if the clipped cell is position before the right frozen columns area.

To work this around, you can call the Rebind() method of RadGridView, after the column width changes.

Applying alternation count does not alternate rows correctly when having both pinned/unpinned rows.

Copied values are not pasted in the proper cells. This makes it seems that the pasted values occur in random cells. 
The issue occurs when the ClipboardPasteMode enum property contains the AllSelectedRows value and the SelectionUnit property is Cell or Mixed.

To work this around, avoid using the AllSelectedRows ClipboardPasteMode. Or the SelectionUnit values Mixed and Cell.

When placed in FixedDocument one of the GridView parents is not a UIElement and this throws internal caught exception in ParentOfType methods used in GridView logic. This leads to performance issues in scenarios with many GridViews in documents.

The aim of this bug fix is to avoid such exceptions by default or with some API.

A kind of a workaround for the user: resize any column/the entire window or collapse the row details.

The column group headers are not displayed when the DisplayIndex property of the GridViewColumn objects is set before the control is loaded.

To work this around, you can set the DisplayIndex of the columns after the RadGridView is loaded.

GridViewDataColumn doesn't respect FallbackValue when the source property returns DependencyProperty.UnsetValue