Katarina's Q and R bug

I just finished a game where I was playing as Katarina. About level 11-12, after I leveled up my ulti for second time, I was unable to cast my Q and R skill. I am very sure that I had no problem with my keyboard as I tested in the chat, use same keyboard while typing these and also, I tried casting the skill with my mouse by clicking. It didn't work. Neither my Q nor my R worked. I exited and re-entered the game to see if it would fix, didn't work again. The only thing that solved was.... to die. I died once and the bug fixed itself. Please fix this bug. Thank you.