The article at https://getpocket.com/explore/item/the-hidden-signs-that-can-reveal-a-fake-photo is about 20 or so pages long, but the print preview only shows 4 - skipping most of the middle of the article content.

There's nothing of note in the console when opening the print tab modal.
But I do see this when initially loading this page - possibly related?

JavaScript error: data:image/gif;base64,R0lGODlhAQABAAD/ACwAAAAAAQABAAACADs=, line 1: SyntaxError: illegal character U+0001

I don't know that this is all Pocket articles, but I spot-checked https://getpocket.com/explore/item/what-we-owe-a-rabbit?utm_source=pocket-newtab and got the same result - 4 pages instead of ~20.

Looking at the page, this looks like bug 1417615. Maybe we could reach out to pocket to work around that for now though?

Bug 1640197 helps with this, and once the fallback fragmentation we have it in a state to ship, this shouldn't be as bad an issue.

sfoster: If you want, you can enable layout.display-list.improve-fragmentation and you'll see all the pages (albeit with some overlapping content).