Sorry for the cross-posting, but for me this has gone on for three days now; and others have confirmed that this is happening to them, too; and that -- if and when you call in to Hyatt GP -- the MyElite rates are indeed bookable:

One can see at the hotel site a MyElite rate (telltale signs: low, familiar prices, ending in $xxx.20 which, when multiplied by 1.25, equal the Hyatt Daily Rate). But when you click on <Check Rates> the MyElite rate does not show up.

Yes, I know that all properties have the discretion of not giving MyElite rates, and, yes, I know that since the inception of MyElite rates it has sometimes been necessary to log in and then log out, refresh, clear cookies, and just try, try, and try again ... but the bug I am referring to is something different. As ephemeral evidence, last night as I was trying the n-th property for the umpteenth time, a MyElite rate tab was suddenly there -- first time in two days ! -- and yet vanished again and was unreproduceable there or elsewhere.