Unable to manage gateway with Xfinity App

I have new internet and it is working as far as being able to connect to wifi and get online, but I'm not able to manage the network because the App says that my gateway is offline.

I've tried going in through the browser based managment portal (10.0.0.1) and while I can see most of the settings, they can only be changed with the App, but the app won't connect. I'm sure you see the problem. 

I was able to get a live chat with someone yesterday, but they were unable to fix it. After going through dozens of restarts I can't get past the automated phone tree because it now says it's waiting for the restart to finish before it will let me talk to anyone. Clearly, I'm online so the restart is done, but they don't see it on their end.

Can someone please help me break out of this endless loop. 

For additional background: The installer set up one gateway but the wifi was defective so he swapped it out. The new gateway worked to get us connected, but now we can't manage this modem. I suspect that this modem just needs to be provisioned and the first one removed. This is a simple fix if someone would just talk to me. 

Please help ASAP