I flew two AA flights last October and it took me more than 3 months to earn mileage on AS! I entered my AS FF# on the reservation, but didn't see anything after a few weeks.. Filled out the online form, still nothing heard.. Called customer center after 2 months, the flights were manually entered, but then shown as "denied" after a few days. Called again after 3 months, the agent had to manually credited me and it worked finally. Not sure if it's because it was an AA basic economy ticket but I'm eligible to earn milage according to the earning table.

Whereas on my two LATAM flights, the miles were posted automatically after ~2 days.