• if I search for "Focus", the third movie is the right one. And the imdb_id is correct tt0246628. I'm starting to believe this may be a bug of the gem I'm using (ruby-tmdb).

It's possible the same IMDB ID has been added to more than one movie. If you go to each movie on the website and click an "edit" link to take you to the edit pages you will see a validation error popup if this is the case.