Website loading time (5.22s) only on root

If I access my current test-project on root (http://la-tickets.eu/) the loading time takes 5.22s. If I access any subsite (http://la-tickets.eu/login), which refers to the very same files (since there is a htaccess "FallbackResource /index.php") the load time is okay.

I already tried to remove all Javascripts, and analyzed the site with firefox developer tools and chrome developer tools

  <div class="container-fluid">
          <?php
                $path = explode('/', ltrim($_SERVER['REQUEST_URI'], '/'));
            if(empty($path[0])) {                       // No path elements means home
                 Print ("home");
                     include ("inc/login.inc.php");
             } else switch(array_shift($path))             // Pop off first item and switch
            {
                     case 'login':
                            include ("inc/login.inc.php");
                            break;
                      default:
                        break;
        }
          ?>
          <div id="server-results"><!-- For server results --></div>
</div>

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