Weird results on Fanime hotel site

[OldOtaku]

I was in the second booking window (starting 10:00) today. Around 9:45, I started checking availability for the Marriott and the Hilton, which was good. Then, starting around 9:56, availability of various types of rooms started disappearing. Strange, because you'd expect people in the earlier window to book as soon as possible, not at the very end. At 9:59, only one type of room at the Marriott and none at the Hilton had availability. OK, great, I got into the Marriott. But then around 10:10, out of curiosity, I checked again, and there were many types of rooms at both hotels available that had been unavailable at 10:00. This is not the first year I've seen this. Does anyone have any idea what's going on here?