Kalista's W spell

When uses her W spell, then it's often bugged. Some reasons why is it bugged:

1. if I use w from outer bot turret to dragon then it sometimes goes to enemy outer turret, or just stay under our turret. (This happens usually, and sometimes after staying under turret flashes to dragon, and NO, I had 43 ms, no lagg or etc.)
2. this happens always, if I use w from mid laner outer turret to baron/rift herald, then the ghost will stay at baron's place, won't move or etc. just plays it's voice and fly in one position. And the bad thing in it (for the enemy) that the ghost never disappears, so it's like a pink ward active until not destroyed.

Sorry, I couldn't take pictures but I really hope that you can fix this! I like to play kali, and use her W in fair way. :)