Jetpack – Infinite Scroll – Custom Post Types – Polylang

So I have several problems,…

The JetPack – Infinite Scroll is working nearly perfect. so it’s working on my index.php where I call posts.

1.
It does not work on my custom post types, is it even possible?

2.
Also I am using the plugin Polylang, so if I change for example to spanish – it does not load anything sadly, but works with default language english.

Okay I found out that the mixxing of the languages.. kills the infinite scroll when using polylang.

add_filter('pre_get_posts', 'get_default_language_posts');

function get_default_language_posts($query) {
    if ($query->is_main_query() && function_exists('pll_default_language') && !is_admin()) {
        $terms = get_terms('post_translations'); //polylang stores translated post IDs in a serialized array in the description field of this custom taxonomy
        $defLang = pll_default_language(); //default lanuage of the blog
        $curLang = pll_current_language(); //current selected language requested on the broswer
        $filterPostIDs = array();
        foreach ($terms as $translation) {
            $transPost = unserialize($translation->description);
            //if the current language is not the default, lets pick up the default language post
            if ($defLang != $curLang)
                $filterPostIDs[] = $transPost[$defLang];
        }
        if ($defLang != $curLang) {
            $query->set('lang', $defLang . ',' . $curLang);  //select both default and current language post
            $query->set('post__not_in', $filterPostIDs); // remove the duplicate post in the default language
        }
    }
    return $query;
}