Katarina's Q R and Back

when I was playing Kat apparently at some point My Q my R and my back buttons became unusable at some point in the game, it felt like they were on cooldown for a long time... I even relaunched the whole client and it still persisted. Apparently it got fixed only after I died. It was really unpleasant and I hope people will check into this so it wont happen to anyone else ( this was ranked so the bug was frustrating )