devices are connected to wifi network, but not to the internet

Yes, it was activated remotely by an Xfinity agent.

Victor, Got it. No unsolicited Direct Messages to Customer Support. Thanks for the reminder. ... Could you also comment on my internet issue: the xfinity Gateway not working as advertised ?

What specific devices are not connecting to the service correctly?

Thank you very much for the clarification. Do the devices that cannot connect to the internet have any type of error message, or just no internet connection?

On my iphone, in Settings - Wifi, the wifi network name has a checkmark next to it to show that the phone is connected, but underneath it says "no internet connection." In my Xfinity app under Wifi - Devices, the iphone is not listed.

There are no other error messages, just "no internet connection"

Okay, thank you very much for that information. I would like to take a further look into your issue from our end for you. Can you send me a direct message with the full name and complete address for your service? 

To send a direct message [private message]:

   Click the "Direct Message" icon or  https://forums.xfinity.com/direct-messaging

   Click the "New message" (pencil and paper) icon

   The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there.

   - As you are typing a drop-down list appears. Select "Xfinity Support" from that list.

   - An "Xfinity Support" graphic replaces the "To:" line.

   Type your message in the text area near the bottom of the window

   Press Enter to send it