Here's the thing about Lux.
It's because of all her abilities.
All of her abilities are effects, light effects.
They face the camera no-matter what like the trees in Mario 64.
Why is this important?
Because the light effect you see isn't an accurate representation of the hitbox.
This can't be fixed unless Lux is given an actual 3D mesh effect for her abilities.
This is why many players face the "It didn't even TOUCH me" cause.
This is also a problem on Morgana and Annie.
Morgana's Q has a 3D mesh which is far behind the actual detection box of the ability, you get rooted before the 3D mesh and not after.
Annie on the other hand only uses pure effects, best seen on her base skin. If you W stun a champion, they're stunned before the fire was even out.
This is fixed with SG Annie, giving the one playing Annie a disadvantage.