The majority of QF fares ex-Australia to the USA now have a sales restriction and may not be sold in the list of countries below. This is why Brazilian travel websites are unable to price out the cheaper tickets and drop the YQ.
TICKETS MUST BE ISSUED ON THE STOCK OF QF AND MAY NOT
BE SOLD IN ARGENTINA/NEW ZEALAND/BRAZIL/COLOMBIA/
PARAGUAY/URUGUAY.
TICKETS MUST BE ISSUED ON THE STOCK OF QF AND MAY NOT
BE SOLD IN ARGENTINA/NEW ZEALAND/BRAZIL/COLOMBIA/
PARAGUAY/URUGUAY.