Bank Account is different between Invoice Header and Payment Schedules

Hello,

This does not happen often but once every 4 months or so, where when an Invoice is created, the Remit to Bank Information in the Invoice Header is different from the one in the Payment Schedules.

The user is creating a standard invoice on a blanket PO and they do not change anything other than the date/amount etc. They accept the defaults and not changing any data.

Summary: Why and how does my Remit to bank information differ between my invoice header and payment schedule?

What setups should i be checking? Have you come across this?

Thanks.