so it’s something to do with your theme….which can be kind of hard to troubleshoot
<?php comments_template(); ?>
you’ve already checked for this I see, is it in your page.php (for pages) as well as single.php (for single post view)?
Also, do you have anything referring to comments in index.php?
<?php comments_popup_link('ADD COMMENTS', '1 COMMENT', '% COMMENTS'); ?>
This is what I have in my index.php, its just a link to commenting, rather than including the comment template as that would clutter my home page
Then you can look into positioning of the code…. compare to other themes I guess to make sure your code is in the right place
it’s usually above the <?php endwhile; ?>
or <?php endwhile; else: ?>