comment form not showing, while comment_status is open

In trying to get comments to work, I’m having the following problem:

I’ve created a custom post type where the ‘supports’ argument includes ‘comments’. however, the comment form is not showing on posts of this type. When I echo $post->comment_status, it returns ‘closed’, but if I look at the database row for the post in question, the comment_status field is set to ‘open’..
Also, I tried commenting the
if ($post->comment_status == 'open') : ?>
check in my comments.php file, but then if you submit a comment it is refused, saying comments are closed on the post.
I find this very curious, as you can imagine..
(commenting in general is allowed in the settings, as well as comments on the posts themselves)

won’t you please help me