Very strange. I'd call AA Advantage & ask them about it? I didn't receive my 100% miles bonus for a US credited flight since it should've posted the day the FF programs merged. I called & the Advantage desk saw the history & gave me the miles with an apology that it was missed. I'm sure they can explain what happened or credit you. I've never had miles disappear at AA, so I anticipate this is a fluke with the merger. Good luck