Adding the_tags to theme not showing up

I have an odd issue I can’t figure out.

I’m trying to modify my theme so it shows the tags for that post at the bottom of a post. I’ve added the function to the bottom of the post on the single.php page and it works perfectly by showing the tags.

On index.php however, I paste the same exact code and it does not show the tags at all. No errors either. The code I’m using is:

<?php the_tags('Tags: ', ', ', ' '); ?>

Pasted here..

<div class="entry">
<?php the_content('Continue Reading &raquo;'); ?>
<?php the_tags('Tags: ', ', ', ' '); ?>
<?php wp_link_pages(); ?>
</div>

I’ve added the word test after the function and it shows up on the home page where I expect the tags, so I know I’m modifying the right theme/page.

Any thoughts? I’m stumped.