comment box still appear under post

Hi guys, not sure why my post , still have comment box despite I already disable it under discussion settings uncheck it

 

use css code to disable it : .comments { display : none; }

 

I found it , the comment is appear in old post, new post don't have

 

I believe you need upgrade your WordPress version, which should resolve your problem; please try it and let me know how it goes.

 

I noticed the old post whereby I used to able comment box is there , Yup I already have the latest WP version and disable comment box. Now all new post is without the comment box only those old post which I used to able. Actually have to manually go every old post to disable. I just forget it , using anti spam to straight remove those spam comments on my old post.