New added product tabs not visible on products page

Wordpress: 5.2.4
Theme: Divi v4.0.4
Plugin: WooCommerce 3.7.1

I am trying to add a new custom product data tabs to the product page, following instructions from the WooCommerce docs:
https://docs.woocommerce.com/document/editing-product-data-tabs/
After I updated functions.php new tabs ar not visible oin my product page
Is there some additional thing to do, or some action to activate new tab?

– I edited functions.php in the child theme (active) per instructions.
– Renaming and hiding other product tabs is working – changes are visible in the products.
– When I inserted code to add new tab, file was updated without errors or warnings, and no related info in the logs.
– When I opened one of the already existing products, new tab was not visible.
– Tab did not exist in the page html code
– When editing existing products, or creating new products, I did not find option to add New tab.
– woo_tabs module also did not have option for new tab.

Child theme functions.php code:
(when I printed out $tabs in the example bellow, the printout contained the info on new tabs)

<?php
add_filter( 'woocommerce_product_tabs', 'woo_new_product_tab' );
function woo_new_product_tab( $tabs ) {
	
	// Adds the facts tab
	$tabs['facts_tab'] = array(
		'title' 	=> __( 'Facts', 'woocommerce' ),
		'priority' 	=> 12,
		'callback' 	=> 'woo_new_product_tab_content_1'
	);
	// Adds the facts tab
	$tabs['knowledge_tab'] = array(
		'title' 	=> __( 'Did you know?', 'woocommerce' ),
		'priority' 	=> 15,
		'callback' 	=> 'woo_new_product_tab_content_2'
	);
	//print_r( $tabs );
	return $tabs;
}
function woo_new_product_tab_content_1() {
	// The new tab content
	echo 'The Facts';
	echo 'Some facts about the product';
}

function woo_new_product_tab_content_2() {
	// The new tab content
	echo 'Did you know?';
	echo 'Some fun tidbits about the product';
}