DNS Address Can't be Found

How do you create the subdomain? Do you use cPanel?

Yes, cpanel… and confirmed it was added to the domain manager (this is at bluehost)

And when you add a new subdomain, are you able to access the subdomain before you add the wordpress files? Usually there is some default files in the webroot which should show when you go to the subdomain in your browser.

Another test… I was able to get the WP installed in a subfolder under their main domain. It found the database. I changed the appropriate index.php and htaccess file.

I can login:
https://www.slyjamesfirm.com/jandn/wp-login.php

But, I get an error on the site:
https://www.slyjamesfirm.com/jandn/

I created another subdomain to test your theory “are you able to access the subdomain before you add the wordpress files” and, no… I couldn’t access it with just the standard files added on the folder creation.

https://jamesandnoland.dazium.com/