[GAMEPLAY] Sion E (Roar of the Slayer) sometimes 'stops short', sometimes doesn't do damage

When using Sion E on minions to shove them, sometimes they will stop short. It seems to be when they are getting shoved into enemy champions, or into cannon minions. They get shoved 100-200 units, then stop just short of the champion (or sometimes they just stop short overall). I've lost hundreds of damage of poke in lane due to this - it definitely has a fairly significant effect on the game.

Also, when shoving it into a minion wave, sometimes the 'projectile' minion will simply pass through other minions without doing damage. (This also occurs with Janna tornadoes. Another bug, but might be related).