Apache2 subdomain not found after addition

Here is a situation

I have example.com domain pointed to my server where Apache2 runs. Currently I have two confs (one for HTTP and one for HTTPS) that accepts example.com requests and shows page thats stored in folder /var/ww/html/example

HTTP conf (example.com.conf)

<VirtualHost *:80>
ServerAdmin webmaster@localhost
DocumentRoot /var/www/html/example
ServerName example.com
ServerAlias www.example.com
ErrorLog logs/example.com-error_log
CustomLog logs/example.com-access_log common
Redirect permanent / https://example.com
RewriteEngine on
RewriteCond %{SERVER_NAME} =example.com [OR]
RewriteCond %{SERVER_NAME} =www.example.com
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

HTTPS conf is basic conf generated by certbot with no changes

But what I want to achieve now is to have subdomain demo.example.com which simply points to root html folder /var/www/html/ (so if I type demo.example.com/some-folder is shows content of this folder)

So I´ve tried this

HTTP conf (exampledemo.com.conf)

<VirtualHost *:80>
ServerAdmin webmaster@localhost
DocumentRoot /var/www/html
ServerName demo.example.com
ServerAlias www.demo.example.com
ErrorLog logs/demo.example.com-error_log
CustomLog logs/demo.example.com-access_log common
Redirect permanent / https://demo.example.com
RewriteEngine on
RewriteCond %{SERVER_NAME} =demo.example.com [OR]
RewriteCond %{SERVER_NAME} =www.demo.example.com
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

HTTPS conf is basic conf generated by certbot with no changes

But when I added site and restarted apache, I am getting not found page that I have on my server as fallback so this configuration probably does not match my conf

HTTP conf (000-default.conf)

<VirtualHost *:80>
DocumentRoot /var/www/html/not-found
</VirtualHost>

Can anyone please tell me what I am doing wrong?

It seems that your configuration is conflicting with the default configuration 000-default.conf which is serving the "not found" page.

1. Disable the default configuration:

sudo a2dissite 000-default.conf

2. Check the DNS settings:

nslookup demo.example.com

3. Check the Apache configuration:

Make sure that your new configuration file exampledemo.com.conf is in the correct directory /etc/apache2/sites-available/ and that it has the correct permissions.

You can also check the Apache error log for any errors related to the configuration. The error log is usually located at /var/log/apache2/error.log.

Then restart Apache:

sudo systemctl restart apache2