Caitlyn auto attack bug?

I saw this posted back in May, and never had any problems until I just recently started playing again.. And now it's happening. Ping is fine, FPS is fine.

when I try to auto attack, it switches between three things: A normal auto attack, an auto attack that doesn't register, and an attack that registers when I actually shoot, and not when the projectile makes contact with the champion/minion/creep. It hasn't been consistent to doing any one of those, it would switch between the three making it difficult to accurately cs or poke or engage in a real fight.