@hotwired 

I would place two of the powerline adapters in the same room just to see if they are even capable of seeing one another or even all four. If the floodlights are causing enough noise to interrupt the signal you may have to use other plugs then what you originally did.

If you say plugged a couple or all four in the same room, and none can pair then they may have coincidently failed at the same time of the ring install.

@Tony I absolutely did move ONE of the rings to the same room as the "transmitter" then even to a second room. I have managed to get ONE to connect for a minute, then it kicks off after a minute or two OR when I try to connect a second one via the app. Very strange. I do have a second TP Link product - the AV1300 that has behaved FLAWLESSLY so I will try to send the powerline adaptors back under warranty and just be happy with the AV1300 WiFi extender. 

@hotwired The strangest thing. We had an all day power and internet outage. When the power came back on (but no internet yet), the powerline adaptors all connected themselves immediately and flawlessly. When the internet came back on overnight, the cameras also came back on (all 5), and powerline adaptors still going strong. We'll see what happens when I plug the ROKU back into them (right now ROKUs are using the WiFi extender or regular WiFi). Any theories on how shutting internet down for a spell would correct the issue? I BELIEVE but can't sWEAR that I already "rebooted" both the modem and router a couple times during all this to no avail. 

@hotwired 

It might have been related to the router giving an IP that was already taken by another device.

@hotwired -- after a power and internet interruption due to a storm, all is running perfect. Boxes connected without my intervention even. Tech has a theory that my installation of the cameras (being hardwired into the electrical system) caused a similar "conflict" like if 2 devices had an IP sharing conflict. By interrupting the power, all the devices had a chance to find a "seat" so to speak. 

@hotwired 

That makes sense.