OK; I see that this system is massively outdated.
I suggest to as soon as possible updating all plugins, WordPress and themes that may need to, in order to be safe with your install.
I exported the Database and the Public folder.
Then I created a local install where I had to disable MultiSite and then edited the Database (user and site) + as well the WP-Config file to match the new install.
I added HTPPS just to have the same as you do.
The DIV "woocommerce-variation-price" is completely empty on the failing products:
hidden link:
<div class="woocommerce-variation-price">
<span class="price">
<span class="woocommerce-Price-amount amount">316,00<span class="woocommerce-Price-currencySymbol">€</span></span>
</span>
</div>
hidden link
<div class="woocommerce-variation-price"></div>
The only difference I find is that the failing product is translated, the working one is not translated.
But for example "Real Fini Baia del Re" as well is not translated and has the same issue.
I see through in the translation of those products that variations are not translated even if the product is translated (Lux, for example)
There was a setting once for this in WooComerce:
https://toolset.com/forums/topic/problem-with-woocommerce-views-add-to-cart-always-reloads-page/
(Different issue but could be related)
That setting does not seem to exist anymore in WooCommerce?
In any case to solve this issue I:
- disabled all must use plugins and customizations to the WP-Config
- Updated WordPress and all plugins/theme
- activated just WPML And Toolset together with WooCommerce (and all related AddOn Plugins)
Strangely I needed to set up WPML + it's WooCommerce AddOn completely from scratch.
No products are on the lists, I needed to create new ones.
I am not able to replicate the issue with that product.
The ShortCode "{!{wpv-woo-buy-options add_to_cart_text="Acquista"}!}"
But my translations include the variations, something that I missed in some of the products of your live site.
I must try to solve this on your install or a staging copy of it, as locally it seems this issue is not even replicable on the very same install.
Can you try to:
- add a new product in a native language
- add variations as WooCommerce wants it
- translate the product
What happens with this product to the front end?
I also need to know if you get any PHP error when you enable PHP and AJAX debugging on the site:
(define( 'WP_DEBUG', true ); define( 'WP_DEBUG_LOG', true ); define( 'SCRIPT_DEBUG', true ); define( 'SAVEQUERIES', true );)
I suspect there is a PHP fatal where you usually see the price, or some other error displayed.
Locally it's adventurous to even deploy the site, as you see it is not really helping.
Maybe we can (we should, it's our only chance) proceed online, or on a staging site.
I suspect after above steps we will know already much more.
It may become required to disable plugins and theme.