[GAMEPLAY] Picked up a sphere with Syndra's W, but couldn't throw it

Here the gif where it happend:
https://gfycat.com/DenseIdolizedGuineafowl It looks like i cast my W at the same moment where the drake does his knock back. I still grab the sphere and the timer for using the sphere starts, but i couldn't actually throw the sphere. Above my abilities you can see the "That ability is not ready yet" message popping up when i tried throw the sphere.