Xfinity tells me I am offline...

Something to contact the ISP about. 

What Orbi model do you have? 

What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too? 
Be sure your using a good quality LAN cable between the modem and router. CAT6A STP is recommended. 

Be sure to disable any MAC Address randomizers on phones and pads while at home:
https://community.netgear.com/kb/en-orbi-knowledge-sharing/netgear-mobile-applications-and-androidapplewindows-devices-faq/2457046

Jackson2 wrote:

When I open the Xfinity app on my phone, it tells me my home internet is offline. But, it is not

As FURRYe38​ pointed out, this is a question to ask Xfinity technical support.  The Xfinity 'app' is checking something to determine the status of the network connection.

It could be:

• When the Xfinity equipment located at your house is on-line, it opens a connection to an internal server (similar to the way "Internet of Things" devices like smart plugs, light bulbs, thermostats, etc. do)  The Xfinity app might connect to that process and check for the presence of a specific identifier.
• After looking in the database, the Xfinity app might attempt to connect to the Xfinity device at your house.

The point is that whatever the Xfinity app is doing, it has nothing to do with the customer's equipment that is connected to the Xfinity device placed in the home.

Thanks for the replies.  Unit is Orbi RBE 972 SB (RBE971), firmware v. 9.13.1.2, modem is Motorola MB8611, connected with Cat6A cable (not sure about STP, but I think it is the flat one that came with the unit).  I'll check the MAC randomizers on the link given.  

I've chatted with Comcast support twice today, then was escalated to a phone support agent who tried remote stuff with no luck.  Finally scheduled a visit from a technician in a couple of days.  Everything else connected via wire or wireless to the system is "online" just fine and I can even connect to Comcast/Xfinity and check email on a computer.  But, when I open the Xfinity app it tells me my home internet is offline.  However, after playing around with the app, I can sometime get to my email with multiple button taps.  A lot of hoops to jump through just to get to "check email"!  Something is wonky with the app, but I was just making sure there is not some setting with the router that needs resetting.  

I have found that contacting Technical Support (from any company) often depends on the capability of the agent.

(I once went through 8 hours of frustration with a technician on site replacing equipment over and over, only to have the last person I called say, "oh. your account is coded wrong.  please try it again."

Used up an entire day of this poor guy's life, for no reason.)

The person you got on the phone may not have understood that the only equipment provided by Xfinity might by the MB8611 modem (or is it yours?).

It might be useful to ask, "how do I check the status of my modem?"