Scoreboard CS count faulty [GAMEPLAY]

so it's happened a number of times and I'm not sure if its a bug or something but the problem is I would check the scoreboard to check CS count. When I would open it, it would show one number, then a dramatically dropped number, then it would go back. For example enemy Lee Sin had 43 cs at one point, then it dropped to 11, then it went back up to a number that made sense. would really like to know if this is a bug or not because it throws me off