Zilean's Rewind, Time Bomb COMBO

Hello there, I am a big freaking nerd for time things, and Zilean was the perfect champ for me, however, there is a slight bug, of course I can do the bomb, rewind stun combo, but for some odd reason, whenever I do it in quick succession, it doesn't rewind my Q, I think this has something to do with the Rewind not counting the Q being cast or something? Someone please help! ;-;