Solved
Name of Wi-Fi has been changed to CoxWiFi after disconnecting.
The router showed orange light today, I pressed the bottom behind the router. Then, the original name of Wi-Fi in setting on the all devices was disappeared, or, turned into CoxWiFi.
Now, I could still use the internet though I need to click the CoxWiFi and log into my account to connect internet on all devices.
Is there anything should be Fixed?
Try logging in to your router again. It sounds like you are connecting to the Cox WiFi rather than your own router.
Try another factory reset. If your using a white Cox gateway, make sure your holding down the button for 60+seconds. The network name(SSID) should match the one printed on the bottom of the gateway. If it still doesn't work, try swapping the gateway out at a Cox store.
