Bank Account on Invoice doesn't populate in Payment Manager

EBS 12.1.3

We entered two invoices for the same vendor with the same invoice date, same site, etc., both marked to be paid electronically.   When we ran the payment process one invoice had the bank account associated with it and the other invoice did not.  Looking at the invoices, both show the bank account on the invoice and both show the payment method as electronic.  The bank account has been set up since 2010, so it isn't new information on the vendor record.  Any thoughts as to what might cause this to happen?  Also, at one point, I saw an article explaining