Calculate tax button is not creating a tax line when invoicing a specific supplier, while other supp

R12.2.5

We use automatic tax calculation in Payables, but we have one supplier where this functionality does not work and I'm not sure why.  A "normal" supplier has "Allow Tax Applicability"  set on the "Tax and Reporting" menu, and the supplier site has Calculate Tax = Yes.

Assuming an approved and received PO, we enter the invoice matched with the PO and click "Calculate Tax" and it applies our default sales tax.

But with this particular supplier, the "Calculate Tax" button seems to have no action.  No tax line is created.   I've checked and unchecked the tax applicability and the calculate tax flag and re-saved the records, and even verified that the "AUTO_TAX_CALC_FLAG" is the expected values in the ap_suppliers and ap_supplier_sites tables (views).