Zac invisible throughout his entire leap animation

I just lost lane to a renekton (ranked game where their team snowballed off this) due to a zac being able to gank me twice in a row both times being invisible throughout his entire E leap animation, their renekton even knew there was a bug with his leap, and i would have not been snowballed as much as we were cause its renekton he hits like a fucking truck while being tank.

First gank i know you wouldnt see Zac right away from fog of war but even after i got knocked up his model was still gone, second gank from a bush again i saw the indicator but yet i still couldnt see zac travelling across the screen at all. third gank when my Xin zhao and I are fighting renekton, Zac ults but he never grabbed me and i got hit without seeing him activate the ult at any point, just a random splash from his passive as the blob flew out.

This is causing people to have way less reaction time than usual, well..cause you cant see him at all at times.