ABILITIES LOCKING OUT DURING MATCHES - NOT ABLE TO ACTIVATE

I have recently come across an issue that has caused players to no longer be able to activate an ability, in some cases multiple abilities halfway through a game.

Not only is this momentarily frustrating, but it actually last the entirety of the match, making it entirely gamebreaking for yourself and possibly your entire team.

This has happened to me recently as Sion and Maokai, most severe case was a match that I was jungling as sion in a close matchup and after backing, I got into a teamfight and was unable to activate my Q W or R. This was a major letdown for my team as R W and allow for very strong teamfight initiating and we proceeded to lose 3 teamfights in a row resulting in a loss where we had been previously domiating the mid and teamfight game.

I have spoken to a few other players who have also recently had this issue arise, any insight or explanation as to how or why this would be happening would be much appreciated as I have ruled out all potential third party software and hardware issues being the cause.