I'll add to the chorus. Just attempted to add a game to one of my lists, and ever after I see the green bar saying "List Updated," the new game is nowhere to be found. (Oddly, the new number ranking for the games that were previously on the list are saved, as if the new game was added correctly.)
This is exactly what happened to me.
Ditto. I know it's not a priority but lists are one of my favorite GB features and them being so busted for so long is really starting to bum me out.