If you display this page by clicking Shipments for a load from the List of Loads attached to a plan, the shipments appear in two tabs: Assigned Shipments and Unassigned Shipments.
If you display this screen by clicking Shipments for a specific load from any other List of Loads, it displays only the shipments for the selected load.
If you display this screen by clicking Load Build > Work with Plan > Shipments > Assigned, list will present all shipments attached to the current plan that are attached to any load on the current plan.