@David-TP Thanks for your reply.  I downloaded the firmware, ethernet connected a PC to a satellite X20 unit, and went through the process to upgrade the firmware.  That just hung immediately, showing a circling icon for 40 minutes.  I then tried on the main unit, which failed immediately with a message asking for that latest version of firmware.

CBC1952 wrote

  @David-TP Thanks for your reply.  I downloaded the firmware, ethernet connected a PC to a satellite X20 unit, and went through the process to upgrade the firmware.  That just hung immediately, showing a circling icon for 40 minutes. 

  @CBC1952 

In my experience, this may happen when firmware file is locked by Windows. When browser can't read firmware file, it will not produce error message. It'll hung with circling icon.

Check that you haven't put firmware file in restricted folders such as root of drive C:, and also in properties of unzipped firmware file make sure to Unblock it if it says it is blocked, like it does here:

  @CBC1952 David, the file is on the desktop and unlocked. And it didn't cycle on the gateway, it just failed because it said it was not the latest rev.  That said, for whatever reason, the network is now correctly showing in Deco i.e. with two active Ethernet links between the gateway and client devices.  It's been OK for 22 hours.  Can you leave this open for a couple of days and if I'm still good, we can close it then.  Thanks CBC1952

  @CBC1952 The problem has gone away.  Please close this ticket.  Thank you.