WordPress - WP_QUERY limit findings to posts with exact same values - php

Question

I am facing some issues with my custom taxonomies in one of my custom post types : I have a page that retrieves my custom posts that have the same taxonomy fields as the page.
For example, one of the custom taxonomies shared between the page and the CPT is 'categorie'. Using a tax_query field in a WP_QUERY, I am able to retrieve the posts that do have the same categorie fields checked as my page's, but I can't seem to find how to get posts that have the EXACT same values.
Here are some visuals in case you're confused :
Page taxonomy with values checked
CPT taxonomy with values checked
So they both have the 'chauffage' value checked and no other one.
Let's say now that I have an other custom post that has 'chauffage' checked, but also 'sanitaire'. How do I tell my WP_QUERY not to retrieve it ?
I've tried to use the operator 'AND' inside of my tax_query array (since it is 'IN' by default) but it didn't work.
The idea I had now was to retrieve all of the taxonomy values and say that the unchecked ones use the operator 'NOT IN', which would work I guess if only I managed to do so. I am only able to get the checked ones, even when using wp_get_post_terms with 'hide_empty' set to 0.
Here's my code :
$page_id = $wp_query->get_queried_object()->ID;
$page_category = wp_get_post_terms($page_id, 'categorie', array(
'hide_empty' => 0
));
// var_dump($page_category);
$page_client = wp_get_post_terms($page_id, 'client', array(
'hide_empty' => 0
));
if($page_category) {
$buffer = array();
foreach ($page_category as $category) {
array_push($buffer, $category->slug);
}
$page_category = $buffer;
}
// var_dump($page_client);
if($page_client) {
$buffer = array();
foreach ($page_client as $client) {
array_push($buffer, $client->slug);
}
$page_client = $buffer;
}
$tax_query = array(
'relation' => 'AND'
);
array_push($tax_query, array(
'taxonomy' => 'categ_article_activite',
'field' => 'slug',
'terms' => $page_category,
'operator' => 'AND'
));
// var_dump($page_client);
array_push($tax_query, array(
'taxonomy' => 'client_article_activite',
'field' => 'slug',
'terms' => $page_client,
'operator' => 'AND'
));
// var_dump($tax_query);
$args = array(
'post_type' => 'article_activite',
'meta_key' => '_article_principal',
'posts_per_page' => 1,
'meta_value' => 'on',
'tax_query' => $tax_query,
'order' => 'ASC'
);
$query = new WP_Query($args);
EDIT : I forgot to mention, I also thought about using the operator 'NOT IN' for the values I do not want to retrieve but since the people that are going to use the website may add taxonomy values, it would require to go in the code add this specific value which is not an option