Are you talking about award seats? If so, it would be helpful to say so.
QF uses Amadeus, in which inventory is loaded 355 days out. AA uses Sabre, in which inventory is loaded 330 days out. Thus, QF flyers always have a 25-day head start on available award seats. As you don't say what date you're looking at, it's impossible to know if that is the reason.
I'm not aware of any evidence that either AA or QF limits the number of seats available to AA flyers (compared with what is available to QF flyers). However, there have certainly been instances of AA agents being unable to 'see' available seats on QF. All you can do is tell them to keep looking or call back and try a different agent.
sorry. this is for reward in december. i am under 330 days. expertflyer shows 3 seats available, but when i call AA they tell me they dont see any award seats. i have spoken to two different agents now. should i keep calling?