Knockups causing skillshots to miss

This happened three times today in two different games. The first game, I was playing as Vel'Koz, and twice when my ally Blitzcrank knocked up an enemy and I fired my Q right at them, my ability didn't hit because the enemy was in midair. The same thing happened the next game when my ally Cho'Gath knocked up an enemy and I as Jinx fired my W right at them. In all three cases, it looked like the ability passed under the enemy, but if the enemy had been on the ground they would have been hit.