Originally Posted by
Top of climb
Not that it probably helps your current situation but you might want to know why this is happening... your flight is operated by a three-class 74A sold as two-class. The First Class cabin (rows 1-4) are blocked. Hence why all 9 seats are X'd out on your seat selection screen.
However, I mentioned above, a dummy booking of 4 F seats on a 4 class plane shows F as being full as they are all "X'd" out.