I have 5 Decos around my house (three purchased in November 2018 and two more added to the network in late August this year). They've generally worked great... until tonight. At exactly 12:00 midnight, I lost my internet connection on all of my devices. I power cycled the modem and router and noticed that the modem still had a connection -- in fact, if I connect an ethernet cable directly to the modem, the internet seems to be running perfectly fine.

However, if I connect the Decos to the modem, the units are unable to obtain a connection to the internet and I am not sure why. I have tried swapping the unit that connects to the modem with one of the other Decos in the house (and changed it to be the "main Deco" in the app), but that did not solve the issue. I have rebooted the systems multiple times but also to no avail. What steps should I take to try to solve this?