Order by Caching is not working

I upgrade to Codeigniter 3.1.9 from 3.1.4, in codeigniter 3.1.4 my order_by is working under cache, but not in 3.1.9, I checked change log there is not mentioned that it is removed or not.


example code:

$this->db->start_cache();
$this->db->order_by("COL", "DESC");
$this->db->stop_cache();


$this->db->get("MYTABLE")