I am trying to search for all films with a certain keyword and I would like to include any potential adult films that have it. My request string is formatted as:

https://api.themoviedb.org/3/keyword/[keyword_id]/movies?api_key=[api_key]&language=en-US&page=[page_num]&include_adult=true

If for example you take the keyword id 260863 which corresponds to 'hardcore' and definitely has adult entries which can be seen when normally searching on the TMDB website, the results are:

1. Uncut Gems,
2. 10 Years Of Q-Dance: De Feestfabriek,
3. The Night,
4. Gritando!,
5. 海蒂,躺下,
6. Intimate Heat,
7. Hardcore,
8. Fracus & Darwin With MC Enemy: Blu The Roof,
9. Provinciales en chaleur,
10. Hardcore El Picante,
11. Under The Influence: New York Hardcore

Which are all marked as adult: false

Am I doing something wrong with my request? How can I ensure that i get any potential adult films as well?