"Ping lock?"

I was playing as thresh in ranked and i was trying to peel for my carry but whenever i pressed q,w,e or r it simply just pinged.. this has never happened before and i was so worked up about it because we lost that fight and the game because of that bug.. my fingers were not on any other keys aside from q w e r, i check and my g or v were not pressed down.. no idea why this happened but i am now back at 0lp because of it.. please let me know what i can do. i play on quickcast if that helps anything