DataGrid sorting no longer works with dynamic data, it errors on the demo too whenever you click a column to sort it.
From my debugging it is related to the QueryableExtension method GetNestedPropertyExpression, and was broken in this commit from 3/5/25. Since an IDictionary is an interface it falls into the new code, rather than it's existing case. I found this bug while looking into another bug with dynamic data that I ran into related to the Dynaimc LINQ library upgrade.
In the second bug, any columns with a space in their title/property string do not sort, and sometimes errors (on the demo just add a space to make it like "Employee ID"). This is related to the QueryableExtension method OrderBy, and how it splits the property string. When calling the method GetNestedPropertyExpression, there is a string split on the space character which causes the issue (since there is a space in the property name). Better splitting logic to only split on the space before " asc" or " desc" would fix this issue.