Zed ult buffer bug with sleep

In this clip I play zed VS Zoe. I gewt hit by sleep and franticly spam r to make it go away but she is out of range. When sleep takes effect you can see my mouse is now spamming to walk back towards tower but instead when zoe gets in range zed ults her. I've never had an ult buffer with any stun or other type of movement impairment ability. I'm pretty sure this is exclusive to sleep.

Please fix riot.