Odd UI bug seemingly after bad lag spike

I constantly get this horrible UI bug in which shortly after I hit a bad lag spike, I can no longer use any abilities or fight, my clicks spam ping and my enter button opens my chat and moves me from full screen to windowed mode and vice-versa. This has cost me numerous fights and games and I cannot for the life of me figure out wtf is going on. I'm incredibly irritated by it and nobody else seems to have even heard of this bug. Can you please shed some light on what is going on and how to fix it? I can't tell you how many times I've been verbally assaulted when this bug occurs and I can't tell my champ to stop running to where I had previously told them to go, usually feeding myself to the enemy team because I can no longer do anything...