I'm migrating my website to a new server and I'm facing a problem since then.
Files are identical, so I have no clue.

I want to access the global user variable in a subfolder, which is a custom php site. 
Here is how I try to access it:

    <?php
    // require global settings
    require_once 'globals.php';
    require_once BACKEND_CORE_PATH . '/spoon/spoon.php';

    // The domain to be used for session cookies
    $cookie_domain = DOMAIN_COOKIE;
    $base_url = DRUPAL_URL;

    // require the bootstrap include
    require_once DRUPAL_ROOT . '/includes/bootstrap.inc';

    // Load Drupal
    drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);

    // get the Drupal user
    global $user;

All includes are working fine, but when i dump the $user variable I get the following (while I'm logged in). At least I guess all includes are working since I got no errors.

    object(stdClass)#14 (6) {
      ["uid"]=>
      int(0)
      ["hostname"]=>
      string(13) "XX.XXX.XXX.XX"
      ["roles"]=>
      array(1) {
        [1]=>
        string(14) "anonymous user"
      }
      ["cache"]=>
      int(0)
      ["session"]=>
      string(0) ""
      ["timestamp"]=>
      string(10) "1535128081"
    }

Note: The XXX in the hostname is edited by me.
Someone has a clue why it isn't working?
Can I ever have this result if drupal isn't loaded correctly?