@David-TP 

I'll give that a shot, but not sure how it would have been just reset when he was out of the country.

  @CraigTompkins I have a couple

Networks that I manage as well as 2 of my own. Mine are the x90 2pk they are doing the same. The others are x55(3) x75pro(3) and are in different locations and they are doing the same started flashing blue but the weird thing is that some of them still have internet and when they take a Screenshot of the wifi in there area it's showing up as the deco name and last 4 mac address digits. Not sure if it's a bad firmware cause I know there was issues with the last firmware update on the x90. I'm gonna try to contact support today.

  @Pezzer44 

Please let us know if you find anything out.

  @CraigTompkins 

Update:  When I arrived all 3 units were flashing blue and the network was missing from the app.  I did "add new network" and set it up like new.  It would not let me use the same network name (which it had been before), so I had to create a new network name.  After doing that 1 of the 2 remote units connected automatically.  The other one required a factory reset and kept failing to connect wirelessly, I moved it and connected it via ethernet and it came online.  Moving it back to it's original location via wifi worked just fine.

So then I had to reconfigure all the devices in the house to use the new SSID which took longer than setting up the new network.

I wonder if there was a firmware update that does not allow multiple networks to have the same name or something and when it got an update it didn't know what to do.