Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/html". Strict MIME type checking is enforced for module scripts per HTML spec

[nathanmartin]

@LXTKay

You can recreate the error by going on the website. The click the register or log-in button. These routes work fine. Then go back and click on a blog-post. This should give you the aforementioned error.

It happens simply by navigating to a blog post.

The first blog post for example tries to load:
https://deploybranch--astounding-syrniki-fb1750.netlify.app/posts/assets/index-CdSh20_-.js

You likely have an SPA _redirects rule of /* /index.html 200

So when the file that doesn’t exist is requested, it’s doing precisely that:

HTML is not JavaScript, and hence the error that you ultimately see in the console.

What does exist is:

https://deploybranch--astounding-syrniki-fb1750.netlify.app/assets/index-CdSh20_-.js

If you view your page source (screenshot above), you’ll see the asset references are relative:
https://developer.mozilla.org/en-US/docs/Web/API/URL_API/Resolving_relative_references#current_directory_relative
./assets/index-CdSh20_-.js

This is why when that page is viewed under /posts/ it then looks for the asset in /posts/assets/

Ensure the asset references are root relative:
https://developer.mozilla.org/en-US/docs/Web/API/URL_API/Resolving_relative_references#root_relative
/assets/index-CdSh20_-.js

Interestingly, when I run your build they are root relative: