Indeed, trying to sort when clicking on any column will not affect the order of the grouped rows. In case you would like to sort the Group, you should sort the grouped item in the group panel. Once you remove the Grouping, then you will be able to successfully sort on a column level also.
Generally, when sorting on a column in a grouped GridView, the sorting should affect the individual items in each group and not the order of the grouped rows.
I will also try elaborating a bit more on how the sorting and grouping in RadGridView work. They are data operations and we internally generate and execute a LINQ query appending a OrderBy or GroupBy clause to the source collection.
For example, when sorting on a Description property of the bound item, the generated query would be:
var result = GridViewSourceCollection.OrderBy(x => x.Description);
So, if you can build such a LINQ query appending OrderBy clause based on the DataMemberBinding or other member specified, then RadGridView will also be able to sort the respective column. Otherwise, this will not be possible.
In case you still have any doubts, would it be possible for you to isolate the exact case in a demo project illustrating it and send it to us via a new support thread? You can take a look at this blog post for a reference on how to isolate an issue. That way I can debug it with the source code to confirm whether we may consider it as a bug.
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