KIndred Bug , marked camp not stacking

Was Watching Huzzy play A-Z lets play on league of legends. This Epsiode was Kindred. If you goto 23:48 in the video you'll notice that He has 4 stacks on kindreds passive. He clears the marked enemy camp shortly after. Still only has 4 Stacks. This video is only 6 days old so it is a current bug. I give a time to skip to on the video so that you can easily see it. 23:48 starts right before he starts clearing the marked camp. Hope this helps make League of Legends better thank you for your time.