Katarina Spells Won't Cast

I recently played a game as Katarina and a weird bug occured that disabled me from using my Q, R, and Recall (B). It randomly happened after I killed the enemy team Kalista (occurs randomly-not just after killing) and returned to normal after I died. I continually pressed the buttons and after waiting a few minutes, it still didn't return to normal. The ONLY solution was to die. I've seen many posts about this bug-Youtube, Reddit, Forums-but no reply from Riot or solution. I added a link to show the problem (It's not my clip). Please find a fix? Thanks!