The problem with Loco Translate for supported languages is that you are creating a custom translation. If you save the custom translation file in the normal location, it will be overwritten the next time WooCommerce updates the master Italian translation file. If you save your custom translation file in the custom location, it will not be updated by WooCommerce and you will need to keep it updated yourself. This could be regular work. Neither options are good. The Loco documentation explains the normal location and the custom location.
I changed my site language to Italian, and “Add To Cart” and “Select Options”?appear correctly in Italian.
Please go to
Dashboard > Aggiornamenti
scroll down to the Traduzioni section at the bottom and double check that it says “Tutte le traduzioni sono aggiornate.” If it says “Aggiorna le traduzioni” then click that button.
If the shop buttons are still showing in English, I suggest a conflict test. Switch to the Storefront theme and deactivate all plugins except WooCommerce. It should work now. Then reactivate theme and plugins one by one and check to try to identify which software is changing the buttons, or preventing them from being changed.
It looks like you are using a custom made theme. Forum members don’t have access to its code. If the above suggestions don’t work, could you ask your developer if he has included any code in the theme to affect button translations.