Polylang not translating Metabox fields [closed]

Turn off custom fields syncronisation on polylang.

I would also then add specific code to tell polylang to copy (not sync) the metas upon translation creation (so when you click ‘+’ it will also copy the metas, but changing the metas after this, won’t sync with other translations):

add_filter('pll_copy_post_metas', 'copy_post_metas', 10, 2);
function copy_post_metas($metas, $sync){
  if(!is_admin()) return false;
  if($sync) return $metas;
  global $current_screen;

  if($current_screen->post_type == 'wine'){ // sustitute 'wine' with your post type
    $keys = array_keys(get_fields($_GET['from_post'])); // an example from ACF
    return array_merge($metas, $keys);
  }

  return $metas;
}

Reference: https://polylang.pro/doc/filter-reference/