I use Ewelink to control cottage heating, lighting, water heater etc from my home. I've had this running for a couple years now.
I use a unique account in NR, devices are shared as required. For quite some time now (> year) I've put up with a periodic (yet often) problem where I get 'authentication failure' . (I use my cell phone or iPad more to control these so I've just defaulted to them when it occurs).
In attempts to fix it, I have sometimes I open the "Edit devices node" and 'pretend' to change things with the credentials (actually just click on it with the mouse), re-deploy and it'll connect and work fine, but again, often it doesn't.
Oddly, when the problem occurs, all Ewelink nodes in the NR editor indicate "connected".
Any thoughts on this?