I have a flexpreis ticket for the Frankfurt Airport to Vienna route at 14:00. Seat reservations are mandatory. I would like to get on the 12:00 train. However, when I try to book a seat only on the DB site, it says there are no seats available. Are there any other solution for me to catch the earlier train? For example, may I ask if the agent at the ticket booth can check for open seats? Or am I out of luck? I suppose I should not have bought the flexpreis ticket if it's not that easy to change trains. #local