how can we find out for a particular property?

I was trying to book one property (Incheon) and compared two different nights. Same exact types of rooms show available for purchase on hyatt.com but only one had reward availability. I called and they confirmed that the other night had no reward availability. I asked about 'standard rooms' and how the availability was exactly the same. She told me that there are capacity controls and that is why I am not able to book with points.

This has me confused if indeed standard room availability is what is needed in order to book with points.