lifeonthego_k I am afraid that availability from B to A does not mean that there is availability from A to B.
QR uses married segments and each origin is allocated a number of reward places for every flight. These reward spaces are for the married segment (e.g. JFK-BKK) not for individual segments (JFK-DOH and DOH-BKK). When flights are first available for booking, almost a year prior to flight, the initial allocation can be booked up within a few days, especially at peak times.
It is quite possible for reward space to be 'sold out' for flights from JFK but still be available from Bkk as origin to JFK.
Have you tried other destinations such as KUL?
Have you looked at availability JFK-DOH and then DOH-BKK? More expensive in Qmiles but you may get lucky.
Of course there is always the possibility of an IT error.