Illaoi's W and tentacle spawn

Sometimes when I want to aa with W, its just cancel few times. Its rly fucked up in fights, cuz I cant move my tentacles. Why auto attacks with W cancel so much? I think Illaoi's W should be more precise. Another "bug" is that sometimes tentacles spawn in places where they normally cant when u use ur ult on enemies or when enemy is a Vessel . I mean tentacles from Vessel and ult sometimes spawn too close to "normal" tentacles from passive and that tentacles last there like normal ones. But can't spawn tentacles in such places, beacuse there must be a some space beetwen each other.