I think my former colleague tried to disable the warning. But it’s still there.
It’s only some products that have it.
Warning: A non-numeric value encountered in /var/www/xxxxxxxxx.dk/public_html/wp-content/plugins/woocommerce/includes/wc-product-functions.php on line 904
Could you please check how it works with some default WordPress themes like TwentyTwenty or WooCommerce Storefront to understand is it our theme issue or not?