Custom Qualifier Attribute not being recognised in Landed Cost Calculations

Hi

I am looking for reasons why a custom qualifier attribute, created and mapped to a custom package/function is not being recognised in Landed Cost Management.

The attribute is using the PO_ADVANCED_PRICE_PVT.G_LINE.order_line_id  to derive the value of a category linked to the item.

The function is below,

create or replace PACKAGE BODY XX???_PO_PRICING_PKG

AS

FUNCTION get_hs_category (p_po_line_id IN po_lines_all.po_line_id%TYPE)

      RETURN NUMBER

   IS

      ln_category_id mtl_item_categories.category_id%TYPE;

    BEGIN

      SELECT mic.category_id

        INTO ln_category_id