Morgana's Ult

I was {{champion:17}} and there was this {{champion:25}} on the other team. You know how her ult has certain range which is shown with a circle around her right? So she threw her ult and it was only me and her in the lane, then I {{summoner:4}} out of her range but I still got stun. **Is there a slight delay for her ult to cancel after you leave the range?**