I discovered that the Questions post type was under the Groups management. However, it also states that even removing questions from groups management, the setting would not apply.
So it clearly means the groups plugin is causing the issue,
Try pasting this code in theme function.php file :
if(!function_exists('
wplms_remove_groups_from_question')){
add_action('wp','wplms_remove_groups_from_question');
function wplms_remove_groups_from_question(){
global $post;
if( 'question' == get_post_type() ) {
if(class_exists('Groups_Post_Access')){
$groups = Groups_Post_Access::init();
remove_filter( "the_content", array( $groups, "the_content" ), 1 );
}
}
}
}