I have had this issue about 3 times over the last 4 months, it consist of last hit on minions not registering and is not due to lag as ping will be sitting at about 20 also going into fights either team fights or solo and my ping jumps from 20 to 400+ only when I go near/engage the enemy champion/s.
This will continue unless I fully uninstall the game and reinstall it then I do not have this issue any more, would I be going mad to this this is some kind of 3rd party/ hack? As after few weeks it will randomly just start to happen again, only been getting this issue the last few months.
I have tried doing a client troubleshooting for problems and full repair and this does not stop the problem, it is only when I fully uninstall the game.
Has anyone else encountered such an issue? Or any idea what maybe going wrong, thoughts would be appreciated!