When using the search widget in Elementor in conjunction with Polylang, once you search, the slug does not contain the language code. Here's a nifty solution that let's you fix this.
If you want to become an experienced developer, you need to learn how to debug. In PHP one of the most prominent tools for this is Xdebug, read my story here. Every know and then I write an article about my developer journey. The topic of these articles may vary from time to time.