In the Warehouse Customers screen, under the Tariffs tab, various tariffs can be configured for inbound and outbound orders.
If warehouse statements have not been generated for a long time and the tariff has changed in the meantime, the incorrect tariff may be applied.
(The tariff is determined based on the start date of the statement.)
This can be resolved by enabling the option to create empty statements for the customer (Warehouse Customers - Customer tab) and collecting statements up to a date before the purchase orders.
An empty statement will then be created.
If you now collect statements again, the start date will be set to one day after the end date of the empty statement.