WP Query filtering by custom category not showing all relevant posts

Question

Here's a question I've been trying to solve all day:

I added a WP Query that would show posts from a category that the admin chooses with a custom field. The post is a custom post type called "Testimonials", and the category is a custom category called "Testimonial Categories". The admin can select multiple categories, and all the relevant testimonials should appear on the page.

The code mostly works, but 1 testimonial is missing. Even stranger, the missing testimonial is different between staging and production sites (the content is exactly the same).

It seems that when a field gets updated on the missing testimonial, that testimonial makes it to the page. But a different testimonial goes missing. Also very strange behavior.

Here's the WP Query:

@php 
    $cats = get_sub_field('reviews_category'); // gets the custom field categories
    $args = array(
                'post_type' => 'testimonials',
                'numberposts' => -1,
                'order' => 'DESC',
                'orderby' => 'meta_value',
                'meta_key' => 'date',
                'tax_query' => array(
                    array(
                        'taxonomy' => 'testimonial_categories',
                        'field' => 'term_id',
                        'terms' => $cats
                    ),
                )
            );
    $query = new WP_Query($args);
@endphp

Thanks in advance for your help. Let me know if I am missing information that can be useful.

Answer 1

@jacob-peattie answered the question in his comment - I used the wrong key to set the number of posts my query generates. Swapping numberposts with posts_per_page solved the issue.

Here's the final query:

@php 
    $cats = get_sub_field('reviews_category'); // gets the custom field categories
    $args = array(
                'post_type' => 'testimonials',
                'posts_per_page' => -1, // this line updated
                'order' => 'DESC',
                'orderby' => 'meta_value',
                'meta_key' => 'date',
                'tax_query' => array(
                    array(
                        'taxonomy' => 'testimonial_categories',
                        'field' => 'term_id',
                        'terms' => $cats
                    ),
                )
            );
    $query = new WP_Query($args);
@endphp