“Your comment is awaiting moderation.” message not working as expected with reve

When a new comment is submitted the unapproved comment with “Your comment is awaiting moderation.” does not appear when per_page option is set to a number higher than the number of existing comments – 1.

I display the comments with:

wp_list_comments(
	array(
		'avatar_size' => 0,
		'walker'	=> new Walker_Comment_custom(),
		'reverse_top_level' => true,
		'page'      => 1,
		'per_page'  => 5
	)
);

Here the chronological order of the comments is reversed, and a max of 5 comments is returned with per_page = 5.

When a new comment is posted, and there are more than 5 existing comments, the new comment with waiting for approval message does not appear. Just the most recent 5 approved comments appear.

If per_page is increased to 1 comment more than the comment count, the comment waiting for moderation appears.

I am expecting the most recent unapproved comment to be displayed first.

Is this a bug or a limitation?