Why doesn't my DataTables sort correctly?
Please check the following:
1. Is the sorting column configured in the View ?
You need to make sure the column used to sort is also displayed in the view.
So, if you configured the view to sort by the Entry date ( the date when the entry was created):
Or, if you defined the sort field in the GravityView shortcode (which overrides the view configuration):
...then, you need to make sure the field is also available in the view configuration on the multi-entries tab: