Thanks to all on this thread for the advice. Have a QR award (4 seats SIN-DOH in Y) in a few months time and noticed the missing baggage allowance (despite AA Platinum/OW Sapphire status as well). Went through several lengthy calls and chat sessions with no resolution and AA claiming everything was fine (and that regardless of what the ticket said, my OW Sapphire status would give me baggage).

I followed a similar script on the phone and finally got an AAdvantage agent on the 4th call who spoke with OneWorld and then worked with the rate desk to manually add the baggage allowance and re-issue the ticket. Confirmed on the Qatar website/manage booking and by calling directly that they see the updated allowance (1 bag per passenger).

For those who are also stuck, keep trying and press the agents that this is a known issue and they can reach out to OneWorld for more information and work with the ticketing/rate desk to get it fixed.