The Users' Guide sticky has a caveat for members, fairly and prominently up toward the top of the page, that says:
" AAdvantage Account
AAdvantage – My aa.com account is showing zeros! – AA posts miles in batches, and you may experience a few hours (or if it is the first Saturday of the month, as far as Monday,) where you can not read your account detail. Situation normal."
Not unusual at all.