Why is the parameter reset in the polylang plugin?

Question

WordPress

I'm trying to set up the url so that, depending on the current language, they are formed in a similar way:

• mydomain.com/en/address-1
  
• mydomain.com/ru/address-2
  
• mydomain.com/en/
  

To do this, you need to enable the setting: The language is set from the directory name in pretty permalinks

But it is constantly reset when saving:


Who faced this, and what is the solution?