Just seen this:
No amount of adding or removing whitespace or text around that point fixed the preview. (The server side rendering worked.)
In this answer.
The issue is not the markdown rendering, it is a bug in the post text.
The post contains a
</pre> too much, which breaks the preview.
<pre> ^\d+(\.\d+)+$ ^\d+(\.\d+)+$ </pre> should work. </pre>
With a little luck, the actual post doesn't show the missing line break, but the actual problem is the
I updated the post and it shows fine now.