We had this problem twice in OKW studios. It was obvious that the carpet had just been wet vac'd. It was very noticeable on entering the room and then we got used to it. We never had the problem anywhere else(so far).
We have had the problem at OKW but never at SSR. I have found that the smell is related to high humidity inside the room. At OKW the room had sat vacant for a couple of days and the AC, which is a de-humidifier, had not been on.
At SSR, there is a sensor on the AC control and if the room isn't occupied, the AC shuts off and the humidity increases leading to a mildew problem. Maybe your room had been vacant for a couple of days.
Fortunately we have never had a mildew problem the last two times we have stayed at Saratoga! Sorry that you had the problem with both rooms~ mold/mildew are tough Hope your next stay will be mildew free~!