It’s long ago since the last time but pimatic-echo got a new release. I bumped it to 0.6.0 because it supports only nodejs from version 8 now. I don’t think it makes sense to support older versions anymore. Apart from this, I hopefully fixed the issue that the devices cannot be found anymore (at least for now). I hope that this change lasts a little bit until Amazon breaks it again.
If you still have issues please try to remove the devices from alexa.amazon.com. And please be patient, sometimes it’s not working at the first try.