Does anyone know why the movie is no longer on Netflix?
Because a license expires and is never forever.
Probably because Disney belongs. And since Disney has now founded Disney + it wants all films & series only on their provider, and therefore take down all films & series that they have sold to Netflix.
Yes, that's strange, because a few months ago Netflix still had Spiderman 2. Now you can find the film on Amazon Prime, but that's not the reason. Because there are some films or series that can be found on both platforms at the same time.