Should I be concerned? Booked a flight in January for next month Atlanta to Barcelona in Premium Select and used Global upgrade certificate which was confirmed at booking into D1 and selected seat 4A which was confirmed. Today, when I log on to Delta either through the website or app, I show I have seat 4A. If I pull up the same flight as if I was booking a new reservation today and check the seat map, the seat I have confirmed shows an X which signifies that a seat is unavailable for advance selection versus showing an outline of a person which signifies the seat is occupied. Same scenario applies for my return flight in December. I called Diamond line and was told I have 4A as a confirmed seat but was not given an explanation as to why the seat I have confirmed shows an X on the seat map today versus the outline of a person. To make matters even more interesting, the person I’m traveling with has same exact situation seated in 3A but today shows with the outline of a person as occupied versus an X.