Supplier Currency default

Hi Team,

We've an OU where functional currency is defined as USD. Since it is out of US we would like to capture all the invoices in local currency which is GBP. 

To set the default currency to GBP at invoice workbench, we have setup supplier currency in payables options as GBP. Even after that, 

whenever we go to Invoice work bench the default currency is coming as USD. I tried creating new supplier and invoice currency in Invoice management was not

defaulted as GBP.

I'd like to achieve two things 

1. After setting up the supplier currency in payable options, new supplier header record should automatically default to supplier currency setup in payable option.