Woocommerce: add content to custom endpoint

Hello,
I created a shortcode:

function check_warranty()
{
	echo 'please code here';
}
add_shortcode('check_warranty', 'check_warranty');

In my account page, I added a custom tab using this code:

add_action( 'init', 'register_new_item_endpoint');
function register_new_item_endpoint() {
	add_rewrite_endpoint( 'warranty-check', EP_ROOT | EP_PAGES );
}

add_filter( 'query_vars', 'new_item_query_vars' );
function new_item_query_vars( $vars ) {

	$vars[] = 'warranty-check';
	return $vars;
}

add_filter( 'woocommerce_account_menu_items', 'add_new_item_tab' );
function add_new_item_tab( $items ) {

	$items['warranty-check'] = 'Warranty Check';
	return $items;
}

add_action( 'woocommerce_account_warranty-check_endpoint', 'add_new_item_content' );
function add_new_item_content() {
	echo do_shortcode( ' [check_warranty] ' );
}

I created a page with slug “warranty-check” and I put in the shortcode:
[check_warranty]

In My Account page, when I click on “Warranty Check” tab, is loaded the page created, without my account left sidebar.
What am I doing wrong?
Thank you.