So i have this tp link extension for a while. I think over 2-3 years and never had a problem like this. I woke up and my dad ask my why he needed to log in into the main network (example: wifi.2.4) and not the tp link network version. When he wants to connect to our main wifi then he needs to login into the tp link. Its saying there is no internet connection. The tp link is just doing fine but he never asked to login. So by default the main password would be "admin" but that also doesnt work. I only have 4 tries left. The main password also doesnt work. For me both wifi's work but for my dad doesnt. I tried forgetting both wifi's, tried to unplug and plug in again. So how do i fix this? Its like it took over my main security on my main network.