TPS63900: Corporate policy restriction CP5

I'm having an issue placing orders for pre-production samples for TPS63900.

Here's the error message: 

• We cannot process line item PTPS63900DSKR in your order at this time due to corporate policy restriction CP5. Please remove this line item from your cart.

Can you comment on this error?

I've seen posts suggesting this is due to PO Box.  However, address for this order isn't a PO Box.

Thanks.