Thank you for reporting it -- also, please post your logs of this so I can view your system specs just in case it's system or hardware-specific so I can note for future reference.
Window capture isn't actually "at fault" itself in OBS, the problem is actually in windows itself, if it doesn't update it's not because of a bug in window capture, it's actually because windows itself did not update the frame. This can often be because of certain ways in which applications can draw frames. I actually suspect that it has something to do with the fact that the lobby window uses flash. You may want to make sure flash's hardware acceleration is disabled, I *think* that has something to do with it last I recall, because I remember someone reporting the same exact thing on browsers that used flash. They had reported the same thing, that the "image was frozen", but they also said that when they disabled flash's hardware rendering, that their browser stuff started capturing properly again. So you may want to try that.