@Born2Code 

Well not sure I can help here but it's not going to let you (probably not) create a wifi network as one it currently sees so what I would do is take down the orbi network completely before you start.  Then delete the network you tried making in the deco app, factory reset your deco and start completely fresh. 

  @Born2Code 

1. If your phone is connected to the wifi of the Deco, the Deco app should show you the info about the Deco mesh.
2. Can you not simpky create a new configuration for the Deco mesh, connecting the main Deco to the ISP modem, disabling the wifi if the Orbi, and specifying the same wifi SSID and password for the Deco?

If you want to replace the Orbi network, why do you want the Deco to join the existing network?  

  @Born2Code 

I didn't want to join the network, I wanted to replace it and I did it wrong.

But I did work around it.  I have 4 Deco units and I configured another one as the router and that worked -- so I have the same network ID and password and everything connects.

The next problem is that I have a MoCa network in the house that works fine with the Orbis, but it looks like the Decos won't connect to it.  It won't configure the remote connected to he router via MoCA.  So I tried to configure it over WiFi close to the router and then connect it via MoCA, but that didn't seem to work either -- the iPhone app never could connect to it.

I need to make sure the MoCA network is working the way it's supposed to and then try again.  My wife and I both work from home, so I may not get another chance to try it until next weekend.

Thanks all.

  @Born2Code 

When you write "I tried to configure it over WiFi close to the router and then connect it via MoCA, but that didn't seem to work either -- the iPhone app never could connect to it.", do you mean that the Deco app does not accept adding a satellite Deco to the Deco mesh, even when the satellite is close to the main Deco? 

Is the satellite blinking blue?