His credit was spurious. Virtually nothing of what he wrote was used in the film. He published his own screenplay later on. I actually like Kubrick’s film. The girl in the film is clearly about 16 or 17. Over the age of consent in many states back then.
But he spent a lot of time with Kubrick and I don’t believe there were any major disagreements during the making of the film.
I think Sue Lyon was 14 when Kubrick cast her as Lolita. A little older then the character in the novel.