Check of connection to dbus-daemon process does not work reliably

I want to check the connection to dbus-daemon process.
My solution is working fine, in case of dbus-daemon is already started, and after that the connection is checked. In case of dbus-daemon process is started during the connection is checked in a force connect loop, there is no OK response (isConnected).
Here is my easy test example:

int Dbushandler::InitializeDBus()
{

  int counter = 1;

  while (counter <= 10)
  {
    QDBusConnection connection_to_dbus = QDBusConnection::sessionBus();

    if (!connection_to_dbus.isConnected())
    {
      printf("Could not connect to DBUS\n");
    }
    else
    {
      printf(Connected to DBUS\n");
    }

    counter++;

    Sleep(500);
  }
}

QT5.6.3 - Windows10/7/XP
Thanks for any kind of feedback.