Sion Q and R bugged

While playing the reworked Sion, It happen that, at a point, my Q (Decimating Smash) and my R (Unstopable Onslaught) got bugged and couldnt be used. I can't explain how it happen but it does two or tree times and I wouldnt be abble to trigger them again during the rest of the game. I have a video here from another player that seem to have the same problem: https://www.youtube.com/watch?v=zlKe3tWyEtw The skill is available and can be clicked on but did not trigger. I hope to see this fixed fast enough, Sion is now one of my prefered Champion.