Random abilities on random champions just suddenly unbind from keys but dont say they are unbinded

Random abilities on random champions just suddenly unbind from keys but dont say they are unbinded. Just as i am saying it. My friends have been having this same problem ive been having this problem like 1 in 30 games. Example: Playing sion running in to just get red by myself no enemies press q no go qqqqqqq no go check to see if chat is up usually the cause hmm no chat oh well lets go help bot press R R R trying to ult no go at all. 15 minutes of spamming abilities typing q w e r in chat going they are not broke why wont they work. Finally i get the idea to put it on smartcast then back to normal and Wa La it works..... too bad ive been useless and we lose the game in ranked. I thought it was just me but this has been happening since 2 patches ago from 4.20. Please fix.