Annie's Stun

I'm not sure where to put this, but when Annie cast's her Q with her stun up, it should immediately drop the stun. Currently, if Annie casts her Q, and an enemy uses Zhonya's, or is Fizz and jumps on their trident, Annie retains her stun and can punish the other player by immediately stunning them. The way her stun currently works diminishes stun once the Q has landed, yet charges her mana the moment it is cast. This doesn't seem right. Any insight? Devs? Anyone?