Text message can get lost in the net and do quite often for me. I've arrived at SFO and texted a friend that was to pick me up. We got back to SJ and sitting in his living room when my message showed up!

Many possible reasons and none of them may apply to AA. Could have been a network outage somewhere along the path. Could have been an issue with inter-carrier connections. Could have been your phone not ID'ing with the FL networks. Multi-vendor solutions are the toughest to track down as everyone tends to point the finger at the others.

When they work, they are great, but gotta expect them to mess up from time to time.