ACF does not directly support Polylang and this would require altering the popup used by acf to allow selecting a language.
I don’t know of any way to accomplish what would need to be done, at least not directly.
I don’t have any specifics but I would look into the following. Create and acf/save_post action. In this action get the language set for the post and get the selected terms. Check each of the selected terms to make sure they are for the language selected on the page. If the language is incorrect then update the term to the correct language.
