Very confused.. flying FRA-DFW 777 and had reserved seat 20C (nice seat or at least acceptable).. did online check in and a notification on top said..."Your seat assingment on the BP may be different than reservation seat" Sure enough I look at the BP and it says 24C. Called AA and they said they show I am in 20C. I using the change seat functionality and simply resubmitted 20C but when I refresh the BP on my mobile it still shows 24C yet the agent sees 20C.. She said to deal with it at the ticket counter tomorrow before the flight and she would put a note in the record.

I thought perhaps it was an equipment change but she said there was no change.

Confused. Any ideas why this happened and how I can make sure I keep the legroom I was hoping for in 20C?