Subdomain network sites goes to 404 page

I installed fresh wp and then active network in subdomain mode. When I create a site under subdomain it straightly goes to 404

Here is the code of config file,

define( 'WP_ALLOW_MULTISITE', true );

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

Here the htaccess

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule . index.php [L]
</IfModule>

My domain was added in cf, I added wildcard a record in DNS. How can I solve this problem?

TIA
K

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