@Aliisaa , you are right that content-post.php
doesn't work
<?php get_template_part( 'content', ( post_type_supports( get_post_type(), 'post-formats' ) ? get_post_format() : get_post_type() ) ); ?>
This theme has 1 post format which is gallery, so that makes the first check always true, get_post_type()
will never be used at all.
But now i've come across another problem, it's not possible to add a comment on the singular post
I can't see that has anything to do with comment on singular. I think the problem is that the post title is not linked, so there will be accessibility issue.
So please try again. this time only change this line, it's down below.
Change this
<?php the_excerpt(); ?>
To this
<?php the_content(); ?>