Custom page templates returns 404 on AJAX requests

Hi there,

When I perform an search AJAX request, on one of my pages it returns a 404, but with a JSON string.

https://www.dropbox.com/preview/Schermafdrukken/Schermafdruk%202017-10-11%2011.00.44.png

When I change die() into wp_die() (Located in ajax_search()) it will solve the bug.

https://www.dropbox.com/s/8yjb58gt3ao4ktd/Schermafdruk%202017-10-11%2011.07.14.png?dl=0

If you can solve this, that will be great!

Thanks!

Kind Regards,
Jarah