Output tax MWST not picked up in Billing Document

Hi SAP SD Experts,

I would be grateful if you can suggest solution in this situation.

There is a PNG customer under AU sales org.  I created a sales order in sales org AU but deliver stock from NZ plant.  As stocks are kept in NZ plant, this way is to save time for stock consolidation in AU and delivery timing.

I manually enter output tax MWST for each item.

But in the billing document, MWST is not picked up.

I go to Analysis Pricing in Sales Order to check.

Here is MWST maintained for AU and NZ in system.

Thanks and regards,

Danny