Internet dopping out every few days at 3am for 24 hours

[RabbitFrost01]

The router is showing only green lights, TV is still connected and works fine. But no other devices in the house can connect to the Internet. This happens every few days at 3am for 24hrs. 3am the next day, everything will auto connect like normal again. Connecting to the router isn't a problem, it's the Internet connection, which according to the router, is fine...