I've noticed this more with the alternate skins than the originals, but it's a major issue. It seems that there are issues with when projectiles land vs when their damage registers for things like basic attacks. I've noticed this several times when laning as Cyber Pop Zoe and Omega Squad Veigar, the animation windups are MUCH longer than in the basic skins, the projectiles travel at different speeds, and they will not register the hit until 2-4 frames AFTER impact. You can tell if you look at the HP bar of a minion as you launch an attack and see it connect. There is a delay, and in some matchups this is crippling because you can still cancel completed auto attacks. This was an old bug with Caitlyn that was notorious enough that she ended up with her being the worst ADC for a whole season.