DocumentRoot remains the same, updated from Apache2 2.2.22 to 2.4.7

I do have the following question. I have moved some websites with the same hierarchy and site structure to a new server using Apache 2.4.7. The old one has 2.2.22. I have changed the default DocumentRoot to /var/www

For testing, I created an index.html file with a dot as content. Now, I do have a file in /sites-enabled/ with the following content:

<VirtualHost *:80>
    ServerAdmin [email protected]
    DocumentRoot /var/www/w2/shop2/website/magento
    ServerName test-w2.de
    ErrorLog /var/www/_logs/w2-error.log

<Directory /var/www/w2/shop2/website/magento>
    php_admin_flag safe_mode Off
    php_admin_value memory_limit 512M
    php_admin_value max_execution_time 600
    php_admin_value upload_max_filesize 128M
    php_admin_value open_basedir /var/www/w2/shop2/website/magento:/usr/:/tmp
    Options -Indexes +FollowSymLinks +Includes
    AllowOverride All
    Order deny,allow
    Allow from all
</Directory>

</VirtualHost>

That was a valid configuration on my old 2.2.22 Apache. Now when I try to enter the domain, it takes the dotted html file! If I try test-w2.de/w2/shop2/website/magento it goes to the correct directory but obviously doesn't work very well ;)

So it's like completely ignoring the DocumentRoot. What's wrong with this error.log says nothing, access.log apparently says it's serving index.html at /var/www. and there were no misconfigurations like when I restarted apache.

I also deleted sites-enabled/000-default.conf. The content was moved to apache2.conf which shows:

...
<Directory /var/www/>
        Options -Indexes +FollowSymLinks +MultiViews
        AllowOverride None
        Require all granted
</Directory>

Of course, before loading the /* that enables the site.