Issue Overview

The Latest Posts block don't always retrieve the Latest Posts.

I had a page with 2 Latest Posts blocks (image below), and when I tried to edit the page, none of them showed any content.

I also had a page with 6 Latest Posts blocks (showing the different options such as Grid, List, Wide etc). Out of 6 Blocks, 3 showed content and 3 didn't.

Steps to Reproduce (for bugs)

1. Insert multiple Latest Posts blocks into content and save
2. Close page
3. Edit page with Latest Posts Blocks

Expected Behavior

Latest Posts Block should always show content when editing the page

Current Behavior

Latest Posts Block don't reliably retrieve content

Gutenberg 2.7.0
Firefox Quantum 59.0.2 (64-bit)
WP 4.9.5