[GAMEPLAY] Vel'Koz Ult gets interrupted doesn't start its cooldown and subsequently becomes unusable

When activating Vel'Koz ult I was hit by a Fizz ult and as expected it was interrupted. What was not expected was that the cooldown didn't start, and even after dying the ult didn't activate or give any indication that I had even pressed the key.

1. Activate Vel'Koz ult
2. Have it interrupted, not sure if it is a specific interaction with Fizz ult or not.

So far it has only happened once, but I had someone in the post game screen confirm that it had also occurred with them.