I recently updated to Wordpress 4.4.1 from I believe 3.5 (it was a very old site that hasn't been updated in a very long time) and since the upgrade, I've been having issues with multiple domains.
I originally had 3 different domains all working off the one wordpress install, serving up different content and styles based on the domain. However, since the upgrade, each domain just redirects to the main domain.
I'm not entirely sure what would of caused this, but any help would greatly be appreciated as I now have 2 sites that are effectively gone.
Thanks!
Found this solution here and it works perfectly!
http://davidmregister.com/dynamic-wp-siteurl/
Essentially, you want to edit your wp-config.php file to contain the following:
/** Absolute path to the WordPress directory. */
if ( !defined('ABSPATH') )
define('ABSPATH', dirname(__FILE__) . '/');
/* THIS IS CUSTOM CODE CREATED AT ZEROFRACTAL TO MAKE SITE ACCESS DYNAMIC */
$currenthost = "http://".$_SERVER['HTTP_HOST'];
$currentpath = preg_replace('@/+$@','',dirname($_SERVER['SCRIPT_NAME']));
$currentpath = preg_replace('/\/wp.+/','',$currentpath);
define('WP_HOME',$currenthost.$currentpath);
define('WP_SITEURL',$currenthost.$currentpath);
define('WP_CONTENT_URL', $currenthost.$currentpath.'/wp-content');
define('WP_PLUGIN_URL', $currenthost.$currentpath.'/wp-content/plugins');
define('DOMAIN_CURRENT_SITE', $currenthost.$currentpath );
@define('ADMIN_COOKIE_PATH', './');
However, I had some issues using this when wordpress was in it's own folder, but worked fine when moved to the root.