I'm flying LGW - AGP with Mrs. and our infant daughter in CE. I'm trying to reserve 2D and 2F but the website doesn't let me choose anything at all. I always get the same "Sorry, we are unable to confirm your seat request(s) at this time. Please try again later or check in at the earliest opportunity in order to choose the best available seat(s)" error although all seats are currently available.

Any clue on what is happening?