I have a TAP-Windows ethernet adapter installed that I use to connect to a Pfsense openvpn on my office, but I wasn't connected to it when I was trying to access the router. I don't think this was...

@kthao I"m having the same issue... Internet works fine, but I can´t access the configuration page. I'm cable wired to the router, no other cable pugged besides me and the modem. Wireless works fine...