Hi,

You can remove it with this filter:

remove_action( 'woocommerce_after_single_product_summary', 'woocommerce_output_related_products', 20 );

Or change the count with this one:

function thegem_woocommerce_output_related_products_args_new($args) {
    $args['posts_per_page'] = 4;
    $args['columns'] = 4;
    return $args;
}
add_filter('woocommerce_output_related_products_args', 'thegem_woocommerce_output_related_products_args_new', 999);

Add this code to the functions.php of the child theme.

You're welcome!