plug-in creates a triple opt-in

When I tested this plug-in, I expected it to send a confirmation email to me. Instead, it popped another signup form onto the screen, so subscribers have to fill out their address and name again and click Submit again. Then MailChimp sends a confirmation email (my understanding is that MC requires a double opt-in).

Is this triple opt-in the intended behavior of the plug-in? I read documentation and reviews and watched videos I found online and nothing mentioned this situation, so it was an unpleasant surprise and I had to remove the plug-in, because expecting people to jump through that many hoops to subscribe to a blog or newsletter is not realistic.

I’m wondering whether the behavior is normal for the plug-in or if I missed a setting somewhere.

Thanks.