Cait E + Sej CC Interaction Bug

There is definitely a bug out there involving Cait's E and Sejuani's Knockup (possibly other forms of CC as well, more than likely the case).

This bug basically causes Cait to not be able to cast E in order to escape from the knockup AFTER the ability is cast. In example, my game as Cait with a Sejuani on the other team literally was decided because I couldn't use E to kite away. I would wait for the stun to come and use the ability afterwards in order to trap/kite my way to the back line again or just behind my team, only to find out that my E was basically useless after the knockup. Note: The cast completed, the passive from the E granting a free headshot proc'd and literally did not move me an inch. If this is the first case I'd recommend only seeing if there can be an explanation posted as a response here, but otherwise, this needs to be fixed, I'm sure there have been other games lost because of this, not just mine.

Thank you for taking the time to read this, see you on the Rift!