Mmm, I have only recently done VIP negotiated prepaid (which doesn't have 5x expectations on the old card). It was agoda underlying deal, but that is not unusual.
With the newer card, it is obvious they want people off the older card, so I don't expect any priceline purchases to have anything above 2x at this time.
It seems no one with the old card has tried seeing if the Precheck or Global Entry gets credited, but I am guessing it is programmed only for the new card.
I mean I too find it bizarre too that someone did programming to remove the 5x credit on express deals.