IDR invoices and BU that they got created

Hello

We have Email to Business Unit Mapping configured for all our BUs.

For example configuration on Email to Business Unit Mapping as follows.

Could you please advise what could be the reason that the IDR invoices that sent from aaa@test.com created in "B" Business Unit if we have info as below.

• All supplier details on the document and system are matched.
• This supplier has multiple sites for all BUs, each site has one BU assigned. There is only one site that Site Purpose is flagged as Primary Pay. For example this case Primary Pay is flagged on "A" BU.