Getting a 404 Not Found on changing my WordPress site to use Multi-site feature. Admin and Index file works fine but other posts show 404 error

Question

The domain name is: thexter.com Sample subdomain name is: data.thexter.com

I am able to visit my admin panel and index page but other pages give me a 404 error. ex: visit thexter.com and thexter.com/uncategorized/hello/ visit data.thexter.com/ and data.thexter.com/uncategorized/hello-world/

• Sorry. I am unable to make make the above links. Stack Overflow doesn't allow me to add more than two links. So copy and paste the links in your browser.

The permanent link structure is /%category%/%postname%/ in both sites.

I am using Google Cloud Hosting Service and WordPress multisite instance from Google Cloud Launcher. The specifications are as follows:

Linux xxxxxx-xxxxx-wordpress-vm 4.9.0-3-amd64 #1 SMP Debian 4.9.30-2+deb9u3 (2017-08-06) x86_64

The .htaccess file in my www folder is as follows.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
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>

# END WordPress

The wp-config.php file in my website has the following code inserted in order to create multi-site.

/* Multisite */
define('WP_ALLOW_MULTISITE', true);
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', true);
define('DOMAIN_CURRENT_SITE', 'thexter.com');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

/* That's all, stop editing! Happy blogging. */

The .conf file code is as follows:

<VirtualHost *:80>
        # The ServerName directive sets the request scheme, hostname and port that
        # the server uses to identify itself. This is used when creating
        # redirection URLs. In the context of virtual hosts, the ServerName
        # specifies what hostname must appear in the request's Host: header to
        # match this virtual host. For the default virtual host (this file) this
        # value is not decisive as it is used as a last resort host regardless.
        # However, you must set it for any further virtual host explicitly.
        ServerName *.thexter.com

        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html

        # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
        # error, crit, alert, emerg.
        # It is also possible to configure the loglevel for particular
        # modules, e.g.
        #LogLevel info ssl:warn

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined

        # For most configuration files from conf-available/, which are
        # enabled or disabled at a global level, it is possible to
        # include a line for only one particular virtual host. For example the
        # following line enables the CGI configuration for this host only
        # after it has been globally disabled with "a2disconf".
        #Include conf-available/serve-cgi-bin.conf
</VirtualHost>

I am using GoDaddy as my domain service provider. The * DNS record is pointed to my Server as follows:

DNS * record for thexter.com WordPress multisite

I have tried out all other questions on WordPress multisite topic in Stack Overflow but none of them seem to be a problem. I am just curious about web servers, so I can change any feature related to the servers. I use ssh access.

Any help is really appreciated. Thank you.