505 Error With Permalinks, 404 Error in Default

I just moved my WP installation from a sub directory to my server’s root level. This has caused the following errors to result:

When Permalinks are enabled (as I was successfully using in the sub directory version), I get this error:

500 Server Error

A misconfiguration on the server caused a hiccup. Check the server logs, fix the problem, then try again.

When I disable Permalinks and select Default ugly method, I get this:

404 Not Found

The requested URL does not exist.

However, it does exist. What’s more, I can access the Dashboard fine. It’s only the public blog that can’t be accessed.

What I’ve Checked

1) I followed the instructions for moving an installation as noted here: https://codex.www.ads-software.com/Moving_WordPress

2) I checked the ability to create/write .htaccess files on my server. It shows properly (I think) as:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

3) Also checked that the siteurl and home tables in the MySQL database correctly reflect the root site address and not the old sub directory path.

4) Double-checked the wp-config.php file has the correct linkages to the database.

5) Am using a new database (with the old data imported) instead of the old one so there’s no issue with table_prefix designation being duplicated.

6) Also deactivated all plugins without success.

Any ideas? Thanks in advance for any help!