Site Redirecting to wp-signup.php

I migrated content from our production server to our dev server in an attempt to sync all environments. I used the All-In-One WP Migration plugin.

Now, when I access dev.domain.com I am forwarded to http://dev.domain.com/wp-signup.php?new=dev.domain.com

It sounds like one of the database values must be incorrect and WordPress is forwarding me here because of it. If I disable Multisite, everything seems to function properly.

Here is my .htaccess:

<FilesMatch "(\.(bak|config|sql|fla|psd|ini|log|sh|inc|swp|dist)|~)$">
Order allow,deny
Deny from all
Satisfy All
</FilesMatch>
<FilesMatch "^(wp-config\.php|readme\.html|license\.txt)">
 Order allow,deny
  Deny from all
  Satisfy All
 </FilesMatch>

and my wp-config:

/** Multisite / WordPress Network **/
 define('MULTISITE', true);
 define('SUBDOMAIN_INSTALL', true);
 define('DOMAIN_CURRENT_SITE', 'dev.domain.com');
 define('PATH_CURRENT_SITE', "https://wordpress.stackexchange.com/");
 define('SITE_ID_CURRENT_SITE', 1);
 /** fix for Multisite 'SubDomains' - Not Working for me :( */
 define('ADMIN_COOKIE_PATH', "https://wordpress.stackexchange.com/");
 define('COOKIE_DOMAIN', '');
 define('COOKIEPATH', '');
 define('SITECOOKIEPATH', '');

For me it was changing old domain entries in database tables wp_blogs and wp_site to the new domain of the multisite’s main domain.

I haven’t done this after the migration to a new domain.