The story: I had an award reservation in Biz for me and my wife on my miles from LHR to PHX.
Cancelled the reservation. Got back the miles for both of us. But the fee refund (about $420 each) only for my wife. The refund on the credit card said the ticket# so I knew was for my wife.
I tried to do online Refund Request. After I put my Last name and My ticket#, system said: Cannot process, call reservations.
Called Plat-Pro desk, got a super nice agent. Told her the story. I asked if she wants the Booking Ref#. She said: generally disappear after 2 days (we were 3 days after my cancel) but give me, maybe still hanging there. She found it. She confirmed that she sees all the above (miles returned for both, refund only for my wife). She had No idea why.
She went to Her Help-desk. And they processed the 2nd $420 refund Manually.

first of all.. glad you were able to get the refund... as far as bugs are concerned.. there are bugs all over AA it systems
along with probably every other business ... I am just impressed with what actually works 99% of the time

AA's refund system is often broken, especially with more complicated tickets. To the point that I wonder if it's intentional on AA's part.

It's the same with trip credits and flight credits (and the often not appearing in the account wallet/disappearing and taking the refund desk days to find).

It's not on every refund, but I have definitely had it occur (only on revenue, never award), where I, the booking party receive the refund of my ticket 5-7 before or after the second ticket on an itinerary. Weird, but it does usually seem to work itself out correctly.

I have this error a couple of times, is better to keep a track, AA will send you an email with a subject "Your refund is complete", it will have the PNR#, the Ticket# as well the amount/CC/payment type. if you don't see it after 4 or 5 days, you can always call back and give them the Ticket#.

This happens all the time with me. You can find the hung up refunds that have not completely refunded by going to your aa credits. There will be ticket number or credit/flight number with zero dollars on it. That is your money and they can see but you can not see it.