Originally Posted by
Lux Flyer
To answer your other questions - undoing checkin in the GA's (or reservations) system is done by unseating you. When they updated your FF# and then re-checked you in, the system automatically assigned you new seats based on what you were entitled to for the new FF#.
Are you saying that un-check-in necessarily entails unseating? In this case, when changing fqtv, makes sense. But when I undo checkin myself, I don't lose my seat.