Bug On Yasuo's Steel Templest.

I'm not sure if this happened before, I was fighting as Yasuo with Wukong, I had Stacked my Q ready to trigger it, Wukong ulted the opponents and so I presumed to use mine. Now this is where it comes in, After ulting it said i still at my Stacked Q ready to trigger but in a split second nothing happened, i had the range indicator for the wind but nothing happened, which resulted in shyvana turning into a dragon and thus running away. Was this always possible when having steel templest ready but when someone is already knockup and you ult, you have to restack the Q.