The Yavetz says in Perek Gimel Mishna 21,Divrei Hamaschil vaaf al pi,and divrei hamaschil veemshol

It's actually in 3, 20, and what the chasid Ya'avetz says doesn't contradict the Rambam or mainstream Judaism at all. He simply explains the mishna there which states, "Everything is foreseen, but the (free) will is given (to man)", that a person has a natural leaning which he can overcome, just that most, in his opinion, do not do so, and simply follow their leaning.