Wordpress Disuqs plugin not working properly

Hi I am new to working with Disqus plugin and I have a strange behavior. After I installed the plugin and configured it it show comments without andy styling and without even the add comment textarea just showing the comment and comment author name only

It doesn't even include any scripts related to Disqus plugin .

here is the code I used in single.php

 <?php comments_template(); ?>

here is the result I get

I have tried to disable the plugin and re-enable it then I try using the twentyfifteen theme and every thing worked fine with it but with my theme I get the issue Any help will be appreciated , Thanks in advance

via Chebli Mohamed