Yasuo's Q + Statikk Shiv

We all know yasuo's q counts as an onhit effect on the first enemy hit yes? We know that in previous instances of the game using q with statikk shiv would either proc the chain effect or give stacks. So why now does his q fail to add 12 stacks towards the total shiv stacks now. Casting steel tempest or gathering storm on yasuo no longer stacks towards the shiv effect, im sure anyone else who plays yasuo must have also noticed this by now. You can't say its always been like that because it hasn't, it has only been around since 6.1, i waited till 6.2 hoping that it was noticed and fixed, but obviously not, so i post here in hopes that it does get noticed and fixed.

For the really lazy people who cant be bothered to read a paragraph.

TDLR; Yasuo q isn't stacking properly with statikk shiv