Odyssey Kayn auto attack vfx showing up in FOW

I just played a ranked game and thought something was fishy when the enemy mid laner was knowing where i was at all times and perfectly matching my movements to prevent me from doing anything. turns out that Odyssey Kayn's auto attack vfx were showing up in the FOW the entire game. ive seen bugs like this before but i havent seen it with an auto attack... i know sometimes vis denting blows sometimes do it but i have never seen them do it all game