[Gameplay] Kalista E double casts, kind of makes her E impossible to use correctly

In my last game with Kalista, right after she was re-enabled, I would try to use E to last hit, to poke, to do anything, and the spell would be used, and then cast again, even if I had no spears in any champion, minion, or monster. It would deal no damage, or deal damage if I had happened to auto attack fast enough, but it would go on cool down because it wouldn't kill anything, use another 40 mana, making it extremely frustrating. This occurred to me nearly every time I used the ability.

How to reproduce- 1- Play Kalista 2- Use Rend [E] on a minion, champion, or monster, having those spears deal enough damage to kill the unit. 3- The spell will then be used again after about 1-2 seconds after the initial cast if it actually was reset from killing the unit. You will hear the spell noise, it will deal damage to any spears you happened to put out in the very small window, even if you have none out, it will still occur, and use another 40 mana, putting the spell on Cooldown.