My headcanon of the scene was that Kylo was kind of sneaking onto the ship to get the dice that Luke left there, because he didn’t want anyone in the First Order to see his “weakness.” So he went in, hood up.
STORMTROOPER: “Huh. Wonder who that could be.”
Force users + hoods = complete anonymity. How many people recognized Palps as Sidious when he put his hood up? Obi-Wan on Tatooine? Kylo’s just keeping up the tradition lol.