Check and see what IP address is set for your Modem. It’s probably the same address.
If your router is wireless and you’re trying to hook it up to your modem and the wireless router uses the same IP - things don’t work.
There should be a setup routine for the wireless that allows you to change it. That was the problem for mine.
I think I ended up setting it to 192.168.2.1
This site can’t be reached
192.168.2.1 took too long to respond.