Back to a Single Wordpress from Multisite has caused issues

Hey there. I was using a multisite installation but it wasn't working for me so I changed it back to a single install, but it is causing some strange issues that I can't seem to fix.

The following is in my WP-Config.php

define( 'SUNRISE', 'on' );
define( 'WP_ALLOW_MULTISITE', false );
define('MULTISITE', false);
define('SUBDOMAIN_INSTALL', false);
$base = '/';
define('DOMAIN_CURRENT_SITE', '');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

Could Sunrise be the issue? I am not sure whether to toggle off or not, or where related settings are. I set it up quite a while ago and remember using a domain mapping plugin to sort everything out, which I have uninstalled.

When you go to my homepage, all is fine:

In Admin CP, there is no "My Sites" or any indication that the site is a multisite. It also says "Requires Multisite" when I attempt to install multisite WPMU DEV plugins.

But, I can still access my content on the subdomains, but in fact, all my content.

For example, a recent post:

And, if you add any subdomain to it:

Same content.

The thing is, in search results on Google, a lot of stuff is showing as webmaster.suckmytrend, which was one of our subdomains we had, but have now removed.

What's the deal with all this?