Line break oddity

Posts that I’ve created since installing wp-markdown don’t have this problem, but if I pull up an older post it seems like all the linebreaks are being removed, except around (some) bold/italics.

For instance, this post is supposed to start:

<h2>A beer in the hand</h2>
<p>Last week we were a little light on beer. We were living on the edge! There’s no such issue now. We’re rocking the usuals: Frank, The Whale, The IPA, De Maas and Rutherford B. Haze.</p>
<p>There is still some <strong>Singularity (Nugget)</strong> left, but less than 10 gallons’ worth. Rudy estimates it won’t last the weekend, and I’m inclined to concur.</p>
<p>Our Bidwell offerings this week are going back to our roots: Frank, The Whale, The IPA and De Maas.</p>

However, the markdown editor is showing it as

## A beer in the hand Last week we were a little light on beer. We were living on the edge! There's no such issue now. We're rocking the usuals: Frank, The Whale, The IPA, De Maas and Rutherford B. Haze. There is still some 

**Singularity (Nugget)** left, but less than 10 gallons' worth. Rudy estimates it won't last the weekend, and I'm inclined to concur. Our Bidwell offerings this week are going back to our roots: Frank, The Whale, The IPA and De Maas.

Any idea what could be causing the issue?

https://www.ads-software.com/plugins/wp-markdown/