It reads as if you did this on the same device, first acting as a logged-in user, then trying to act as a guest. You have to admit that in the real world it's unrealistic. This would happen on two different devices instead.
To simulate it, i.e. for testing purposes, you should delete all cookies in your browser for your domain in between actions, or use two different browsers, one for the logged-in user and one for the guest.
Also, you can offer a logout option for logged-in registered users by publishing a Joomla login module, visible for registered users only.