I have ran across this multiple times when trying to use Cash+Points, when booking at an Actual Marriott Marque Hotel wich not allow Cash+Points but yet there's plenty of availability is using only points or just cash???? Kinda defeating the purpose here Mr Marriott business..
Second at certain times when using the Cash+Points the rate is completely different if you booked only cash compared to combining Cash+Points...
So Mr Marriott Business I guess this is called sticking it to your elite customer base to squeeze all the cash you can from everyone!!!!