Woocommerce subscriptions do not update the cart since the last update

For reference, the site I am working on is available here:

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This site has simple and subscription products. When I add a simple product to the cart, such as a coffee bag, the cart updates and the pop-up window "added to the cart" appear. The subscription products behaved in this way also until today, when I updated WordPress and WooCommerce. Now, as you can see, adding subscription products to the cart does nothing.
I downloaded the site, changed the theme and deactivated all the add-ons, but I also have the same problem in that version! Except that in the local version, the subscription products give me an error:

This site can not provide a secure connection. The local host sent an invalid response.

I have taken a look at the section & # 39; network & # 39; In the development tools, the subscription products are sending an XHR request called & # 39; cart / & # 39 ;, while the products that work are not. Any idea why this could be happening?

Is this a known error? With a little loss as to how to move forward!