I'll make this short. I tried in a normal and in 2 customs. Xin's Q sometimes does not knock up, if the target isnt moving, it will not knock up. it does say it knocks the target up, but not the animation, making it seem last shorter then it should be.
Has happened to me too.
Bump, fix rito.
Xin OP, he can't live without a knock up. Of course.
I can confirm, as well as for me it didn't stun or knock up minions at all.
for me it was like a crit strike... every once in a while it works, but most of the time it doesnt. the thing is, sometimes it kinda stuns them in place for like 0.3 seconds if there is no knockup (i think the knock up was shortened by like a lot or something) 
