I have no idea why

But ever since i updated, I will randomly stop walking while attacking. Several times tonight during games as two different champs (Sion and Nasus) I would be going after an enemy champion and would randomly stop walking after clicking to attack the enemy champ. I still had vision on them, so that wasn't the problem, but I would just stand there and do nothing, either letting them escape with minor health, or let them turn around and kill me since my champ wouldn't do anything. And if it was lag then it was only during those times as the rest of the games went fine.