function custom_show_category_description() {
    if ( is_product_category() ) {
        $term = get_queried_object();
        if ( $term && ! empty( $term->description ) ) {
            echo '<div class="category-description-bottom">';
            echo apply_filters( 'the_content', $term->description );
            echo '</div>';
        }
    }
}
add_action( 'woocommerce_after_main_content', 'custom_show_category_description', 20 );