The landed cost only works with the specific Costing Method and Inventory Valuation method. Make sure that you choose Real Price in the Costing Method and Perpetual (automated) in the Inventory Valuation field on the Product Internal Category. Look at the following screenshot for the detailed configuration:
Products related to other categories that do not have Real Price in the Costing Method and Perpetual (automated) in the Inventory Valuation will not be included at the time of splitting the landed cost.
