My profile for Hyatt shows king. On the few occasions I intentionally book two beds, somehow it always overwrites and changes the reservation to a king. Even changing my online profile to two beds before booking the room does not stop the overwrite. Hyatt does not understand why.

Meaning, you may have a similar inexplicable predicament with Marriott. If I book two beds the initial reservation comes back correct. Sometime within a few days it overwrites for a king. When I see online that has happened I call in and they can fix it on a stay by stay basis.

Or verify your profile is for two beds instead of a king.