Ensure that you have enabled PLC by logging in to the router's web-based management page, and going to More Functions > PLC Settings > Powerline.

If your main router works normally but your secondary router's Wi-Fi suddenly disconnects, try the following:

• Check that you have plugged your main router and secondary router to a wall socket.
• Unplug your secondary router from the wall socket and then plug it in again.
• Plug your secondary router into a different wall socket.
• If the problem still persists, restore your secondary router to its factory settings and try again.

Avoid plugging in chargers (including phone chargers and electric bike chargers), microwaves, induction stoves, hair dryers, vacuum cleaners, electric drills, LED lights, or any lamp or light with induction switches to the power line that connects the secondary router and main router.