I just installed the new Dual-Bnd WIFI 802.11ac XB3 gteway and connected it to my Apple Airport WIFI base station. I set the Xfinity modem to bridge mode which I thought disabled the WIFi service. Why is the 2.4GHz led still blinking?
Do you still see your gateway's WiFi 2.4 network name (SSID) being broadcasted ? If not then that confirms that it is disabled. It may be a firmware glitch or it may have to do with the public WiFi hotspot still being enabled.