Devices connected to XB7 Router are unable to network together

No, I am only using the XB7 to produce the SSID. 

Based on what you’ve shared, I can see that all of your devices are successfully connecting to the XB7 and receiving valid 10.0.0.x IP addresses, and they’re able to access the internet. That tells us the connection to the network itself is working properly @user_px279k.

When devices can reach the internet but can’t communicate with each other locally, that typically points to a local network or device configuration issue, rather than the internet service itself.

At that point, the next things to review would be on the device side, particularly with how the Pi server and other devices are configured on the network. For example:

• How the Pi is configured for local networking (services, firewall, interfaces)
• Whether it has a consistent local IP (DHCP reservation or static LAN IP)
• Any software or security settings that may block local traffic

We’re always happy to help confirm the connection and provisioning up to the gateway, but the communication between devices inside your home network (LAN) is managed by the device configurations themselves.

Negatory, the devices all successfully connect on the LAN when used on any other router (TP Link, Linksys, etc). Terminal arp -a command shows other devices when they're all connected on a non-XB7 router, and any device can successfully ping other devices. When connected to the XB7, arp -a returns nothing. All devices have WAN internet access, but no LAN connectivety to local devices. Certainly a XB7 issue. Is client/AP isolation enabled on these routers by default?

We can check on the connection from our side up to the gateway from here. If there is an issue with your device you can always swap that out for a new modem. Can you send me a direct message with the full name and complete address for your service? To send a direct message. 

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• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list

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DM sent with address