[Plugin: Related Posts by Jetpack] Related posts not appearing

I’m having an issue with Related Posts by Jetpack. The related posts only display *sometimes*. If I go to my landing page and click on an article, no related posts appear. However, they appear intermittently when a post is directly linked.

For example, if you go to http://www.hackmycab.com/ and click on the “Buying an Arcade Machine” tile, no related posts appear.

But if you click http://www.hackmycab.com/?portfolio=buying-a-ddr-cabinet, you *may* see them.

The container loads, but is empty:

<div id=’jp-relatedposts’ class=’jp-relatedposts’ >
<h3 class=”jp-relatedposts-headline”>Other hacks to check out</h3>
</div> </div>

I’ve searched these forums up and down and haven’t found a solution. I’ve de/reactivated Jetpack and reindexed my posts multiple times.

Please help, this is driving me nuts!