I am having the same problem with it, but mine is the 46 in samsung with 240 hrz model, I have to keep closing out the app and re opening it to get it to search.... videos are not buffering, but here is the weird part about it.... I updated my samsung TV and ever since this problem has started... another weird problem, you can go to your youtube account favorites and or subscriptions and it will load just fine and buffer..... but if you go back to search mode.... the same video you watched while searching would be there in the same spot you left the video, but it won't reload...

Also another bug I experienced... the video would freeze even if the video had already loaded the entire video and I would have to keep rewinding it to get it to play again, otherwise I would not be able to watch the video, this is so very damn annoying.....