I have an Xfinity Gateway, but use an Asus router for routing, wireless, etc. Ergo, the Xfinity Gateway is acting as nothing but a modem.
Now, I should have the Gateway in Bridge mode for this to work, but it does not. When in Bridge mode, I can not connect my network through the Gateway. So, currently Bridge mode is turned OFF. Now, this makes no sense to me and I am left scratching my head. This means that I have DHCP turned on in BOTH the Gateway and Router (though the IP addresses all appear to be coming, as they should, from the router), there is no sign of the wifi from the Gateway in my home (though with Bridge mode turned off, there should be).
Basically, WHAT is going on???
Did you power-cycle / re boot the Xfinity gateway device after placing it in to bridge mode and connecting the Asus router to it ?