I really appreciate you are trying to help and yes, english it's not my first language. I get what you have said, Victree has access that move in gen 7. I just find hard to believe that the developers let Victreebel learn Poison Jab "by mistake" before the last tutors update. I think that if it worked probably it's because it was meant to work. So in this case i reported the bug just to help the community. But thank's for your observation, it could be that this was just an oversight.