[Risolto] Problem using automatic translation in multiple languages

Background of the issue:
I'm trying to translate my website, which is already in Italian and English, into Spanish and French using an automatic translator. The site I need help with is link nascosto.

Symptoms:
When I select certain pages in the translation management, the checkbox for 'Automatic translation' becomes gray and returns the message: 'You can only automatically translate content from your site's default language (English) to your site's other languages. To proceed, deselect content in your site's secondary languages.' However, my default language is set to 'Italian' in both the user area and WPML area. When I switch to English, it prompts me to switch to 'ITA' view from the button above.

Questions:
How can I resolve the issue with the automatic translation feature not recognizing Italian as the default language?