I have a somewhat similar problem. A few days ago I contacted reservations because a December reservation for Munich that I made in June was not allowing me to request sweet night awards. The reservation agent said that she put the request in the system and I received an email with my sweet night reward request. And my suite night balance reflected that change. Yesterday I noticed my account was down by 25,000 points. When I checked I saw that my Munich reservation which is been unchanged ( except to add the suite night award) showed -150,000 points and +175,000 points on the day I spoke to the reservation agent about the suite night awards. When I called Marriott and spent nearly an hour and 20 minutes I was told that the hotel had gone up in a grade and it cost more. I was aware of the change, but that shouldn’t affect my reservation which was made in June. A Marriott supervisor told me they are “trying” to get that done and get my points back. So far nothing.