I have a new Echo Plus and set it up correctly. It worked great so I was very happy. However, a few hours later, when I use the wake word, Alexa, the blue light spins but doesn't respond to any of my commands. It spins then turns off and does not perform any of my commands. I unplugged it to reboot it. Sometimes that work, but most of the time it just remains unresponsive. I got tired of it and thought it may be defective, so I exchanged it with Amazon. My new Echo Plus acts exactly the same. Works initially, then becomes unresponsive. Sometimes it will respond, but mostly it doesn't. Is anyone else having this issue? I't frustrating me since it appears that this device can be really useful and cool. Help!