Sometimes i cannot use my ultimate or summoners spells

Hello, I am not sure if this is general bug or its just me but i have this problem. Sometimes i just cant cast my ultimate or summoners spells like flash/ignite/smite/ghost just not specific one it happens with everything and every champion. First you might think that Im just silenced or stunned, but when its happening in jungle and my smite randomly doesnt work its pretty suspicious and annoying as well because i died many times because i couldnt use ultimaet/flash because it simply didnt work. I am sure that my keyboard is okay because i never registered any r/f/d button error.