I just ran into this yesterday. I called up to make a 3 night P and C reservation at the PH, which is a total of 30K points. I had 29,300 or so points in my account and I asked if that was ok. The agent replied sure, as long as you have the points by your stay. I then asked to apply a DSU which he also seemed to accommodate.

Fast forward and I didn't get a confirmation email so I checked my Hyatt account. The rate is listed as $399 a night and 18K points are missing- so I PM HGP concierge to get things sorted out. Turns out instead of doing as I asked; the agent reserved me a room at the HDR and applied a 6K per night points upgrade. I'm not even quite sure why he took it upon himself to do that but thankfully the HGP concierge was able to sort things out quickly.

FDW