@mitchellau you should probably start a new topic. I doubt that your problem and the OP’s are the same. My suspicion is that the OP’s issue was here
'menu_slug' => "site-options-${lang}",
'post_id' => "options_${lang}"
should be
'menu_slug' => "site-options-{$lang}",
'post_id' => "options_{$lang}"
