I've seen the room type issue as well - for the Sheraton Schiphol (Amsterdam) airport the Biz card rate allows you to book an accessible room, while none of the other rates allow that. This is the unusual case where an accessible room is not just a variant of a regular room, but its own room type. Anyway, fixed my points booking by emailing the hotel directly and they changed the room type.

BTW: I really would have preferred Marriott to do the same as Hilton, and always assign a different room type for an accessible room. Now it takes a lot of clicking to first figure out if the room type has the option, and then if it is available by trying to book it.