Polylang – cannot translate anything on static first page

Just had this exact same problem on Fullscreen Pro (https://catchthemes.com/support-forum/topic/header-media-title-and-polylang/). But this time it is Decree Pro. Polylang shows me three strings to translate, that's it. Why do you sell these themes as “...our Multilingual WordPress themes with built-in multilingual support. Supports plugin like WPML, Polylang and qTranslate.” if I cannot translate a single thing without help? What do I do now? www.iserver.fi/fysio