I've been seeing this throughout the morning. Right now it says 11 Open Realtime games. I click on the link and it shows 8 open games. (It's not stuck or anything, because it shows different numbers, but it seems to be off every time I click it.)

could be the nested games (same game name/settings, but multiple instances of it). the numbers for daily games were off too, and i assumed that was the case there.

Yes it's because some games are filtered (any game with duplicate settings (number of players, fog, teamplay) on the same board is filtered so that the first created game is only visible till filled.