Tax on AP Payment Request (Issue Refund from AR)

Hello

We issued a credit memo refund from AR to get AP invoice created as a Payment Request invoice for refund transaction.

On AP invoice for the refund from AR, there is Tax Classification Code default at invoice line. However, we don't see any tax line generated even the invoice is validated. (Our credit memo in AR has VAT line generated)

Anyone know that this is an expected behavior on AP Payment Request?

Do you know why we get the Tax Classification Code appears on AP Invoice Line but there is no tax line generated?

Thank you very much