Hi @pureweb
I believe you should add ACF as the post type that needs to be translated. You should be able to do it like this:
add_filter('pll_get_post_types', 'unset_cpt_pll', 10, 2);
function unset_cpt_pll( $post_types, $is_settings ) {
$post_types['acf'] = 'acf';
return $post_types;
}
For further information, kindly get in touch with Polylang support.
I hope this helps 🙂