I've booked a reservation through AA, with several legs on BA. One leg has me puzzled so I wonder if someone can shed some light.

Booked on BA718 from LHR to ZRH. I always take an aisle, so AA agent gave me 2A and said it was both a window and aisle because the configuration is 1-2-1. This doesn't make sense for a narrow body like an A321 so I asked her to double check. She said yes, it's 1-2-1.

I called BA and gave them my reservation number to check, and the agent confirmed that this flight is on an A321 and the seating in first class (Club Europe) is 1-2-1 on this aircraft.

Seatguru shows it as the usual intra-European seating for other BA narrow body flights, which is 3-3 with the center seats blocked out.

Does anyone have an idea what's up?