Loop for shop_order post type not working?

Is your WooCommerce shop_order post type no showing any results? All you may need is to add a post_status into your loop’s arguments.

Add post_status into your loop's arguments

In order to display WooCommerce orders, you need to set post_status to wc-processing, in order to show processing orders.

$args = array(
     'post_type' => 'shop_order',
     'post_status' => 'wc-processing'
$loop = new WP_Query( $args );

while ( $loop->have_posts() ) : $loop->the_post();
//Do stuff

Note, you can also set post_status to any or array_keys( wc_get_order_statuses() ), in order to display all WooCommerce shop orders.

However, for example, in order to get multiple, yet selective, types of orders, you can set this to array( ‘wc-completed’, ‘wc-processing’ ).