Language selector on main menu.

Hello,
i now manage a WP installation with Transposh.
Everything was already setup and previous manager created a menu for the Language.
Italian is the “Default language” and there are 4 more languages.

If i enter the website i can choose the language correctly.
For example: from Italian to English gives no problem.

But if, after that, i want to change language again all the links in the main menu to the other languages are redirecting to English.

i saw this: https://wordpress.org/support/topic/transposh-in-main-menu-translation-links/ but it didn’t help.

Could you please help me?