Here’s an example of working tax_query.
The problem I’ve run into with tax_query is forgetting to nest the array (i.e. ‘tax_query’ is array(array(…)). If you don’t do that, it does not work.
$args = array(
'post_type' => $post_type,
'posts_per_page' => -1, //show all posts
'tax_query' => array(
array(
'taxonomy' => $taxonomy,
//'field' => 'slug',
//'terms' => $term->slug,
'field' => 'term_id',
'terms' => array([your values]),
)
)
);