Bridge mode xb7t disabling lan ports

Hi everyone,

I’m hoping someone can help because I’m completely stuck.

I have an Xfinity XB7-T gateway on the 2 Gbps plan. I recently purchased a TP-Link Deco 7 (Wi-Fi 7) system because I have a lot of devices and was experiencing frequent drops (especially my Xbox and my work laptop during meetings).

The problem:

When I enable Bridge Mode, all LAN ports stop working.

When I turn Bridge Mode back off, the LAN ports immediately work again.

I know that on the XB7, LAN port 4 is the correct port to use in Bridge Mode. I have specifically tested this port and still get no connection.

Here is exactly what I’ve done:

• Unplugged all Ethernet devices
• Plugged only one computer into LAN port 4
• Enabled Bridge Mode
• Waited for the modem to reboot
• Power-cycled the modem again
• Restarted the computer
• Tested again with both my computer and my Deco (separately)

No matter what I do, once Bridge Mode is enabled, port 4 does not pass internet at all.

The moment I disable Bridge Mode, the same port and cables work instantly.

Because of this, I can’t use my Deco system, and I’m stuck using the XB7’s built-in router, which isn’t handling my number of devices well. I pay for the 2 Gbps plan and want to actually be able to use it.

My questions:

• Has anyone else seen XB7-T Bridge Mode completely kill all LAN ports?
• Could this be a firmware or provisioning issue on Xfinity’s side?
• Is there something Xfinity needs to change/reset on my account or modem?

At this point it feels like either a firmware bug or the modem is not being provisioned correctly for bridge mode.

Any help would be appreciated. The constant drops are starting to affect both work and gaming.

Thanks in advance.