Defaulting rule of Currency Cnversion Rate Type

Summary:

Ora Doc says Conversion Rate Type is defaulted from "Common Payables and Procurement Configuration setting for the Sold-to BU. But on our test env, it is derived from Requisition BU .

Which one is a correct product design?

Content (required):

Ora Doc says Conversion Rate Type is defaulted from "Common Payables and Procurement Configuration setting for the Sold-to BU.

How Purchasing Document Header Defaults Work (oracle.com)

But on our test env, it is derived not from the Sold-to BU but from Requisition BU's AP setting .

Which one is a correct product design?

Version (include the version you are using, if applicable):