Comments not appearing at all

Stupid question :
Is it possible that your theme doesn’t include the comments on display?

In addition to settings, your theme must display comments.

The default function provided by WP is comments_template (to use on single.php and/or page.php) :

 comments_template( '', true );

UPDATE —————————————————

I believe there is something wrong with the theme “hueman”.

I installed it on a local WP containing sample contents.

When I go to an article containing comments, I have the exact same result as you get.

If I display the exact same article using a different theme (one of the defaults provided), the comments are displayed.

So I checked the single.php template file of the hueman theme and it use a custom function ( hu_is_checked(‘post-comments’) ).
Used in:

if ( hu_is_checked('post-comments') ) { comments_template('/comments.php',true); }

The problem is: it return null (so the comments can’t be displayed).

According to the theme documentation, we should be able to customize the theme options through the customizer
http://docs.presscustomizr.com/article/113-customizr-theme-options-comments
This option is located in : Customizer > Content Panel > Comments

Unfortunatly I wasn’t able to found it :
I tried on front page, single post, page, never saw it.

So, since the option is not defined, the custom function will always return null.

A quick fix would be to create a child theme of hueman, overwrite single.php template and change the line for:

comments_template('/comments.php',true);

I tested it, it works.

A better solution would be to contact the theme author to see if we missed something or if it’s a bug.