Netsuite While editing line item it automatically removes the dependent dropdown list value that are

While selecting the line item for editing, it automatically removes the Dependent Drop-Down List values that are already filterd using the sourcing and filtering option. It completely removes the value from Dependent Drop-Down Lists.

I have two dropdowns on line item to have category and sub category. While choosing the main category I have created a filter to show only the values related to the main category field on sub category dropdown. This works fine while creating the new line items but fails while editing any field after the insert. It’s getting refreshed and removes the filtered values from the second and showing blank dropdown.