Lax-dfw, believe the flight departed at 1220am.

Checked in on the mobile app and had a mobile boarding pass. Show up at the airport at about 1150 and to my surprise, no AA rep in the terminal. Mobile boarding pass in hand though so shouldn't matter, right? Wrong... Briskly walk to security and am told no mobile boarding passes are accepted that late. Explained there's no rep in the terminal and the kiosks weren't allowing me to reprint a pass. TSA agent went to check with his supervisor and about two minutes later, comes back and says it doesn't matter if they let me through cause I wouldn't make the flight (could literally see the line of people boarding.) Tried explaining I could but he wouldn't budge.

Called AA at the airport and was told all i could do was file a complaint, and to better manage my time. Two weeks later all I got was a voucher for the original ticket price.