Apache 2: querying not existing subdomain is opening the first subdomain

I’ve configured several subdomains in apache within sites-available:

#first.domain.me <VirtualHost first.domain.me> DocumentRoot /var/www/first.domain.me <Directory "/var/www/first.domain.me"> allow from all Options None Require all granted </Directory> ServerName first.domain.me </VirtualHost> 

and

#second.domain.me <VirtualHost second.domain.me> DocumentRoot /var/www/second.domain.me <Directory "/var/www/second.domain.me"> allow from all Options None Require all granted </Directory> ServerName second.domain.me </VirtualHost> 

When I query the non-existing-domain notexisting.domain.me from the browser the URL is still notexisting.domain.me but the content is the one of first.domain.me

I can’t understand why. I would want to redirect to www.domain.me or give a 404 error but everytime the first domain content is opened. As you see there are no mod-rewrite directives and I’ve nothing in 000-default.conf

This is the content of 000-default:

<VirtualHost *:*>     Redirect permanent / http://www.domain.me </VirtualHost> 

And this is the content of www.domain.me.conf:

<VirtualHost www.domain.me> DocumentRoot /var/www/www <Directory "/var/www/www"> allow from all Options None Require all granted </Directory> ServerName www.domain.me </VirtualHost> 

Can you explain me why the first.domain.me is matching all the other domains like dhiashdiuahidhau.domain.me ? How can i fix it?