copy document, purchase order, change ship-to / deliver-to, tax does not redefault

We are setup that PO tax defaults from ship-to

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Problem Scenario>>

Po1 ship-to1 ( functions at normal thru invoice match)

next copy PO1 using copy document in PO core form to PO2    

..... Change Ship-to and Delivert to new location2

.... approve PO

When matching and invoice to the new PO2, ship-to is correct with new location 2

BUT The tax code is coming from the olo PO1

it should redefault on invoice matched to new po

Is there a profile we are missing or a step that needs to be taken?