In this case we would suggest you to perform hard reset on the modem then try accessing internet on direct connection without router.

http://arris.force.com/consumers/articles/General_FAQs/SB8200-Factory-Reset

My SB8200 had the same thing happen last week. I tried factory reset, contacted ISP for signal refresh, troubleshooting concluded modem had failed somehow internally. It’s a 2017 v1, so I bought a new SB8200v3. Now I cannot get a DOCSIS 3.1 connection (blue light) on the new modem. Old modem never had anything but a 3.1 connection. Before I return this modem as faulty, is there anything else I can do? ISP says it’s providing 3.1 capable signal levels and the modem is connected with them as 3.1, but I’m not seeing that. I have 1GB service through WOW! 

This is my status page. I cannot access any other tabs. I’m direct connect to the modem

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@Gralewski2 I’d start your own thread so your info doesn’t get confused with the OP’s as well as sometimes these get closed when mark solved