[GAMEPLAY] Sion ult moves in the wrong direction

While playing ARAM today, every time a Sion on either side or either team ulted, he would move in a random direction (usually the complete wrong way). While I never experienced it myself, I was in a call with a friend who was trying to play and he said it was very frustrating. I'm not sure if this happens on any other map, as I have not tested it myself, but all you need to do to recreate it is play Sion on the Howling Abyss map and try to use his R. Sion will never go where you want him to, sometimes making a U-turn mid-ult; and there is no way to control this in any way. Hopefully this gets fixed soon as the skill is pretty much useless as it is right now! Thanks.

For more specific steps:

1. Play Sion on Howling Abyss
2. Cast ultimate from anywhere in the map
3. Watch as he goes in a random uncontrolled direction