Take it to Go G10:
Play 1,000 Mahjong Games or Begin a game on a Windows 8 device and finish it on your phone.
Description for this is slightly wrong.
It popped for me when I stopped mid game, went off to do something else, and then returned to it later on the same device (I don't own a W8 machine)
No idea whether this is how everyone else is popping it, but this will at least give us a 'solution' to test to see whether this method works for everyone, or whether it is indeed bugged to pieces.