hiroysato

Hello, @bcworkz Thank you for your advice.

I followed How to Setup WordPress Multisite with Multiple Domains

and set COOKIE_DOMAIN domain explicitly.

Finally I succeed to create blog.example.com and news.example.com.

I also set define( 'DOMAIN_CURRENT_SITE', 'blog.example.com' ); as you said.

define( 'MULTISITE', true );
define( 'SUBDOMAIN_INSTALL', true );
define( 'DOMAIN_CURRENT_SITE', 'blog.example.com' );
define( 'PATH_CURRENT_SITE', '/' );
define( 'SITE_ID_CURRENT_SITE', 1 );
define( 'BLOG_ID_CURRENT_SITE', 1 );
define('COOKIE_DOMAIN', 'example.com' );