More tag and it's use on pages. Error: Loads index page not post.

We did a rather unorthodox experimental custom WP theme to be used as a CMS on our company website a ways back. It’s mostly a portfolio website.

Ironically I’ve been wanting to ad traditional blog capability back into the theme. So I went back and created new templates (next time I’m using daughter themes for sure) for our blog section.

I want to be able to use the ‘More’ tag rather than excerpts. however I’m encountering a error that I’m sure is simple little fix but it’s baffling me. I can’t fire out how to engineer the loop to get the ‘more” tag to display that particular post in the correct template. Right now when you click “read more” it loads the index page.

The blog section is not live yet I have not updated the header include with the new navigation menu tot he blog page – but here is a link that should display the working page:

https://www.quesinberry.com/wordpress/blahg

You’ll see a couple of the test posts – one has a ‘read more.’

Any ideas out there? I’ve looked at too long.

Thank you in advance.

Here is the PHP:

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