Surprised to open my Marriott account and try to use SNAs for a stay in May, only to get the dreaded "Suite Night Awards cannot be applied to this reservation" message.

There are multiple updgraded room types and suites which show up when I do a dummy booking for the dates of my stay (like so many different room and suite types that it might be over a dozen). Seems very odd that I am getting this message, unless this is one of the Participating Properties at which you cannot use SNAs.

Does anyone know? Lurkers, any help on that question? It would be really awesome - though I am sure quite difficult - to actually know that list. Thanks.