Gragas Q "no mana" bug

Hi, I was playing Gragas and some weird bug occured. As i got lvl 12 I put one point into Gragas "Q" spell (using ctrl+Q). After that Q stopped working and I couldn't use it. Description said that i had "no mana" and this problem didn't even go away when reconnecting, rebasing or dying as Gragas. I am not sure why this bug occured but maybe it was something to do with other characters in game. When i was lvling Q, i was fighting in teamfight where on my side I had Nami support and as enemy there was Vladimir (some other more but I dont suspect any other characters influencing). Bug lasted till the end of game.

Best of luck when coding!