How to change two row by no reset itemsource value

Thanks for your answer

I'm sorry i missed an important  thing  

i group the gridview by ColumnGroupDescriptor

<telerik:RadGridView.GroupDescriptors>
                <telerik:ColumnGroupDescriptor x:Name="columnGroupDescriptor" Column="{Binding Columns[\ContactTitleWithConverter\], ElementName=ESColumnGrid}"  SortDirection="Ascending"/>
</telerik:RadGridView.GroupDescriptors>

in your demo code i change a row cell data as same as another row  and drag the column header to group 

and the issue is also exist

Is there any solution for this