Unable to sort an anonymous assignment’s inbox by grade

When viewing submissions in an assignment that is set to anonymous and yet to reach the post date, you will be unable to order the submissions by grade.

Turnitin tell us this is behaving as designed due to the anonymity. When you order the view by grades, Turnitin will only see an empty field for the grades column, so it moves to the next column it can order by (which is the submission ID).