Netgear AC1750 R6400 no longer connects to internet

I purchased this AC1750 R6400 Nighthawk about 4 weeks ago. It has been working flawlessly. Not a single problem. Set up was smooth as butter. Then, today, all of a sudden I get an amber light on the internet connection. No connection to internet it says. I have rebooted, shut down, etc. I went through the initial install steps again, 3 times now. I have called my ISP (charter spectrum), nothing wrong there. The modem works just fine when connected straight to computer. When connected to router, it will not connect to internet. I have tried the MAC cloning/spoofing to no avail. I have really enjoyed this router until today. Please tell me there is something I am missing. Thank you.