@Jimmiq said:
Is the API ignoring dates?

Not exactly.

I’m doing this search.
But get same result every time.
Even if I set the gate 100 years in future
https://api.themoviedb.org/3/discover/movie?api_key=YOUR_KEY
&watch_region=SE
&with_watch_providers=8
&with_watch_monetization_types=flatrate
&primary_release_date.gte=2024-01-01
&sort_by=primary_release_date.desc

I tested it now.
Year 2024

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=2024-01-01&watch_region=SE&with_watch_monetization_types=flatrate&with_watch_providers=8
total_pages 28
total_results   550

Year 2034

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=2034-01-01&watch_region=SE&with_watch_monetization_types=flatrate&with_watch_providers=8
total_pages 1
total_results   0

Year 2094

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=2094-01-01&watch_region=SE&with_watch_monetization_types=flatrate&with_watch_providers=8
total_pages 1
total_results   0

For me, the error appears when the century changes.
And the result for any date in the next century or millennium seems to be the same.
It seems that the code has no barrier to this type of typing error.
Year 2104

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=2104-01-01&watch_region=SE&with_watch_monetization_types=flatrate&with_watch_providers=8
total_pages 299
total_results   5979

Year 2124

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=2124-01-01&watch_region=SE&with_watch_monetization_types=flatrate&with_watch_providers=8
total_pages 299
total_results   5979

Year 3124

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=3124-01-01&watch_region=SE&with_watch_monetization_types=flatrate&with_watch_providers=8
total_pages 299
total_results   5979

EDIT
The range of the wrong result is between these dates:

"release_date": "2025-12-10",  
"release_date": "1926-06-25",
"release_date": "",  

Includes movies without a release date.

EDIT 2
I believe the one with the longest release date in the database is this movie.
Avatar 5 (2031)
https://www.themoviedb.org/movie/393209-avatar-5

Hmm ok. So what’s the correct search to get let’s say only movies that are are semi popular and released last 2 months?

@Jimmiq said:

Hmm ok.
So what’s the correct search to get let’s say only movies that are are semi popular and

Semi-popular I don't know how to filter very well.
Maybe sorting by Popularity will help to select.

released last 2 months?

Specifying a time window.
Using:
&primary_release_date.gte= and &primary_release_date.lte=
Example:

https://api.themoviedb.org/3/discover/movie?api_key=THE_KEY&language=en-US&page=1&primary_release_date.gte=2025-04-01&primary_release_date.lte=2025-06-01&sort_by=popularity.desc

or
&release_date.gte= and &release_date.lte=
if you want a specific country, region.