Try to reset at first
IMPORTANT: This will reset any changes that have been made to your Wi-Fi modem settings to date. You may also need to reconfigure your devices’ Wi-Fi settings (network name, password, etc.).
Using a small, sharp object, press the modem’s reset button for 10 seconds.
Once your modem has restarted, follow the same instructions you used when you initially installed it.
Reminder: The default username (Default Wi-Fi network) and password (Default key) for your Wi-Fi network are written on a sticker on the back of your Wi-Fi modem.