When retrieving the movie changes with GET https://api.themoviedb.org/3/movie/changes?start_date=XXX&end_date=YYY&page=ZZZ the json response contains an invalid object. The results array contains an object that has both the id and adult set to null.

{
    "id": null,
    "adult": null
}

With the id set to null, there is no way to identify what changed here.