Multilanguage with Polylang plugin doesn’t work

Hello everyone,

I am using the plugin in question on a site where the multilingual is managed by Polylang. The two languages ​​are Italian and English. I followed your guide for translating the popup step by step but the result is always the following:
– activate the multilanguages ​​option in the plugin
– I set the backend in Italian (switch with the flag in the topbar)
– I set all the labels of the popup, on the Design page
– save, and check that everything works fine in Italian.

– I set the backend in English (switch with the flag in the topbar)
– I find the texts in Italian which I replace with those in English
– except
– I do a test, setting and entering the popups, Italian and English, have become in English, in practice the last language entered.
– I pass again in Italian in the backend, and I find all the texts of the popup in English.

In practice it is ignoring that I am setting the Design, once in Italian and once in English. The theme I use is Sydney.
How can I solve this problem?