I am not trying to defend Marriott, just so we are clear....
Hmm, that's just a term to explain what I mean, not a term I think that means anything in the documents. Let me rephrase for you. If a date is available on the screen, is that better? So, if a date can be clicked on, you can reserve 1 day, right? If it cannot be clicked on, you can't right? So, clearly, Marriott is saying it is not available for booking in one case, but not the other based on some unknown or arbitrary reasoning or policy. Nothing in the document shown thus far says what they must consider available under what conditions. If it is displaying an X, it can't be booked for the search criteria used.
Whether or not it is a website issue is trivial to decide. One merely calls and tries to reserve, which I believe you or someone else said they did and it was still not possible. So, this would say indeed, it's not a website artifact.
So, if someone can find a basis for the claim we want, which is Marriott not showing availability correctly, then we might be able to get somewhere. If it isn't there, then, sure, we can discuss and complain, but, there is no basis for it with Marriott. Unless a document says Marriott must shown allow a reservation if there is a un-reserved room or something like that... Hotels have always used interesting techniques to keep rooms off the record for booking. I've stayed at several hotels where there were no more rooms. Where there are no more rooms, yet I still stay there, clearly there were and clearly they were considered unavailable for booking for reasons known only to the hotel. We know in MVCI case, for example, that some inventory is reserved for weeks vs points. In that case, it's clear that it may show as not available however, one could reserve their week for the same date. I suspect some inventory is reserved for longer stays. The question is, does this violate anything in the governing documents. It violates nothing posted yet.