Game 11446180 Frankfurt
First, I was surprised to get a Possession game with Lord Rat...I had thought Possession was completely out. (I also thought that I had "unfriended" Possession even before that card's ban. So its appearance was surprising.
Second, I did get a Possession and played it. Each time I did, the entire game log disappeared, with the game log now showing only the most recent turn. This sounds like a bug, albeit not--strictly speaking--a log bug, and not an actual game bug.
This is a known problem, and I think it also happens when you play Possession against other players. The easy solution is to use the page-reloading mechanism of your browser (Ctrl-R on Firefox), the symbol usually looks like a 3/4 of a circle circle with an arrow at one end. This works both on the Possession turn as well as the next turn when you are 'back to yourself'.