Nighthawk EX7300 - No Internet

I can connect my NETGEAR Nighthawk X4 AC2200 WiFi Range Extender to the Asus RT-AC3100 router but am unable to connect from the extended wifi connection to the internet. I have factory reset the modem, router, and extender  multiple times with the same negative results.  It all originally worked but after I reset it due to the potential router virus, I have been unable to reestablish the internet connection to the extended wifi.  I was able to connect the extender to the neighbor's router and connect to the internet with no issues.