How to design Tax Rule for Sales order when warehouse belong to another BU

Summary:

Tax Rule design for Sales order when warehouse belong to another BU

Business Unit - Singapore Business Unit

Warehouse from where shipment is happening - Malaysia Warehouse (belongs to Malaysia Business Unit)

Customer - Customer Bill to address Country is Singapore

In this case tax is not getting calculated when tax rules conditions are:

Condition :

a) Bill from country = Bill to country

b) Tax code at item level = TAX_CODE 9

This is because system is checking the item assigned to Malaysia because shipment is happening from Malaysia

warehouse where for same item the tax code is 'TAX_CODE 10' . Is my understanding correct ??