DataGrid Sorting showing Unexpected Result when click on Header of the column containing the same data

Steps to reproduce:
1.Create a datagrid with DataProvider as ArrayCollection of Objects. e.g. DataGrid showing Name and Company
2.Now for Name column different value exists but for the Company column all data is same like all the Name is belonging to Company ABC only
3.Click on the column of Company Header for sorting
4.For the First click one can notice the sorting happened on Datagrid eventhough the records are same for the column Company.
5.From Next click onwards it's behaving properly

Actual Results:
For the First click one can notice the sorting happened on Datagrid eventhough the records are same for the column Company.

Expected Results:
Even for the first click it should not do the Sorting of the data as behaving for second click onwards since data is same in that column

Workaround (if any):