I’m building a filter with AJAX to sort a custom post type loop. Users can filter the loop using two taxonomies “group” and “area”.

Some of the args of my CPT loop are:

   'orderby' => 'date',
   'order' => 'ASC'

The issue is, the filter works great but the result is displayed in the DESC order not ASC.

Here is the code of the filter:

function mysite_filter_function(){

    //groups checkboxes
    if( $groups = get_terms( array( 'taxonomy' => 'group' ) ) ) :
        $groups_terms = array();

        foreach( $groups as $group ) {
        if( isset( $_POST['group_' . $group->term_id ] ) && $_POST['group_' . $group->term_id] == 'on' )
         $groups_terms[] = $group->slug;
        }
    endif;

    //teachers checkboxes
    if( $areas = get_terms( array( 'taxonomy' => 'area' ) ) ) :
        $areas_terms = array();

        foreach( $areas as $area ) {
        if( isset( $_POST['area_' . $area->term_id ] ) && $_POST['area_' . $area->term_id] == 'on' )
         $areas_terms[] = $area->slug;
        }
    endif;

    $tax_query = array( 'relation' => 'AND' );

    if ( ! empty( $groups_terms ) ) {
    $tax_query[] = array(
        'taxonomy' => 'group',
        'field'    => 'slug',
        'terms'    => $groups_terms,
    );
    }

    if ( ! empty( $areas_terms ) ) {
    $tax_query[] = array(
        'taxonomy' => 'area',
        'field'    => 'slug',
        'terms'    => $areas_terms,
    );
    }

    $args = array(
        'post_type'      => 'workshop',
        'post_status'    => 'publish',
        'orderby' => 'date',
        'order' => 'ASC',
        'posts_per_page' => -1,
    'tax_query'      => $tax_query
    );

    $query = new WP_Query( $args );

    if( $query->have_posts() ) :

    while( $query->have_posts() ): $query->the_post();
        get_template_part( 'template-parts/content-archive-workshop' );
    endwhile;

    else :
    ?>

    <section class="section bg-grey section-split--2 height-elastic">
        <div class="container">
            <div class="container-content col-1-2 padding--small">
                <h2 class="entry-title large"><?php esc_html_e( 'No se han encontrado talleres', 'artonyou' ); ?></h2>
            </div>

            <div class="container-content col-1-2 "></div>
        </div>
    </section>

    <?php
    endif;

    die();
}
add_action('wp_ajax_myfilter', 'mysite_filter_function');
add_action('wp_ajax_nopriv_myfilter', 'mysite_filter_function');

Any help would be much appreciated, thank you.