URLs generated by gatsby-script-loader may be negatively impacting my site's SEO

[patricia-tonella]

Hi all 👋🏻

I have a blog built with Gatsby, and I use --prefix-paths to add the /blog/ to my domain (example.com/blog/). All my URLs/paths work fine.

I recently started getting a LOT of warnings in Google Search Console related to 404 pages (892 so far).
This is the pattern message for the 404 warning:

Page is not indexed: Not found (404): https://www.example.com/category/post-name/ (this page does not exist/not live anywhere)
Referring page: https://www.example.com/blog/category/post-name/ (this page exists)

Thing is there's no direct reference to the 404 page on the referring page (as I mentioned at the beginning, all URLs/paths are being generated correctly). The only reference to a path without the /blog/ is from the gatsby-script-loader.

I was reading the Gatsby docs and it looks like the blog path should be included in the page object name. I wonder if the page was built in a way that webpack doesn't include /blog/ in front of the page object?

I'm also wondering if this relative link is the root cause of the 404 pages, and how can I ask Google to stop crawling this partial link.

Any clues/thoughts are very welcome. Thanks in advance!