Programmatically set language?

After poking around in the database of my site, I figured out how Polylang stores its language information – as taxonomy terms, in the wp_terms table. It’s not a perfect solution for a number of reasons, but you could just check what the ID of your desired language is and use wp_set_object_terms() to add the term to your posts.

Ideally you (and I) would use a function native to Polylang to avoid hunting in the database for the term ID, not to mention to avoid having to implement the fix differently on different websites, but I unfortunately don’t know of such a function.

Hope this helps, as far as it can.

Perfect, thank you.