Blinking of orange light on Xfinity Gateways is a result of connection of the device at 10/100 Mbps or lack of communication between the gateway and your modem. To resolve issues, you can follow the series of steps mentioned under:
Turn off the Xfinity Gateway and disconnect the device’s power adapter from the electric socket.
Wait for two minutes and connect the power adapter of the router back to the electric socket. Turn it on and check if the blinking of the orange light continues.
Check if the Ethernet cable connecting the router and your computer is in proper condition. If there’s any physical damage, replace the cable with a new one and check if the issue is resolved.