This happen because you have virtual hosts enabled in your Apache and most probably you disable the default site. What you are seeing in the curl output is the html code of your first virtual host. If you run this command, will enable the default site.
Code:
sudo a2ensite default
You probably will see the "It Works!" page, if you didn't create a homepage for the default site. After that, run again the curl command and you will be able to see the server-status output.
Code:
curl 'http://127.0.0.1/server-status?auto'
Hope helps, it worked for me.
