Adding new blog posts breaks blog path

[claudiopolis]

Hello. Thanks for the great starter theme. Clean and simple, just what I was hoping to find.

In setting it up for my own Netlify account, I found an error.

Deleting old blog posts and adding a new one breaks the path to the blog posts from the blog page, but not from the home page.

I created an example website to demonstrate the issue.

https://gatsby-starter-foundation.netlify.app/

I'm new to Gatsby, so though I will troubleshoot, I will probably move slow, so any help here will be greatly appreciated. TIA!

[claudiopolis]

2 points to clarify. I made all the edits online with the Netlify CMS, nothing local. The new blog post is reachable from the home page, but the blog page adds a "blog/" to the URL between the base and the post's slug.