Its not really a surprise though, those in the first priority group of 7+games in 2023/24 are the fans most likely to want to buy a ST, those in the second window would have don't it in the last two days already and those left are probably away fans or the Mitoma+ members who have lost interest...
There may not be any ST seats left, the club doesn't sell every seat, a set number are kept for match by match sales so if that limit has been reached they may not be any season tickets available now.