Or maybe because it's the top of the tree? I speculate idly. See the ginormous screenshot.

This is an html snippet from the generated index.html doc:
<h3 class="outdent" id="seealso">See also</h3>
Getting Started
Contact Support
What's new in RFC Auction Systems v3
FAQs
How the Help Center Works
</article>
And here's a snippet from a topic where the seealso is good:
<h4 class="outdent" id="seealso">See also</h4>
<div class="see-also-container">
<div><a href="/help/How-the-Help-Center-Works.html">How the Help Center Works</a></div>
<div><a href="/help/Contact-Support/Setting-up-a-Service-Desk-Web-Portal-Account.html">Setting up a Service Desk Web Portal Account</a></div>
</div>
</article>
Odd - tried this out a minute ago and I saw exactly what you're seeing.
Then tried it again with different topics and it worked just fine, and now I can't make it fail again.
First time I was using all top level header topics.
I keep poking at it and see if I can figure out why it's not working sometimes. Maybe there's some text that breaks the Html in the text but of course I can't dupe it now.
+++ Rick ---
If I'm reading the snippets correctly, the see-also-container div did not get generated? The one obvious difference to me is the topic type for the top of the tree topic. Did I use the word topic enough in that sentence? Let me know if there's anything else I can contribute.
If you can repo reliably let me know...
I can't make it fail anymore.
+++ Rick ---
Happy Monday.
I've regenerated and deployed multiple times. The see also contents in my main/index/top topic renders as plain text and not actual topic links. Let me know how you want to proceed.