Cannot Cast Spells or Summoner Spells when loaded in

I just played a Lux game where for the first 5 mins i was disconnecting and reconnecting because every time i loaded in i could move around normally but i could not cast any spells, i would press E and nothing would happen, i would press P to open shop and nothing, i would slam down on my D and F key and none of my summoner spells would proc.

My team had no sympathy for me and we lost because my Mid lane had a free 5 min head start and i was infuriated that i lost because of something i could not control.

This happens once every few games and every time it does i have to hope that i only have to hope reset the whole client once, as in i have to exit the game and close the client and re log in then reconnect. If the same problem occurred i had to repeat the process at least 3 times before things would function properly.

HOW DO I MAKE SURE I NEVER HAVE THAT PROBLEM AGAIN?? PLEASE AND THANK YOU