Diana's autoattacks are bugging

Sometimes,when i play it happens that i click on a minion to autoattack it,and the animation starts,but sometimes finishes half of the animation,and then the animation goes back to begining and this repeats itself 2 or 3 times and then she finally finishes the attack.This,to me is a big problem because of her passive.I run some AS in my runes,so while the autoattacks are bugging her passive could've already been activated.Let me know if u had such an experience.