Factory reset C3000, have internet but can't access router wifi network

[Joshbseen]

So I did a factory reset on an C3000 N300 wifi cable modem router combo. 

We have 3 computers connected; 2 via wifi and 1 via ethernet.

All 3 can launch browsers and access various web sites. 

None can launch apps like Steam, online games or update apps like Malwarebytes without getting a "network error-check internet connection" message.

None can access the modem's admin interface via it's default IP address(192.168. 0.1.) without getting a "not connected to your router's wifi network." Even the ethernet computer.

Both the wifi computers randomly lose connection.

Is there a work around or is this an ISP issue?

[plemans]

Try going to 192.168.100.1

Also, make sure IPv6 is enabled. 

Try a different DNS Server. Here's a few for ipv4. Also remember to change the ipv6 dns server if ipv6 is enabled
CloudFlare 1.1.1.1 and 1.0.0.1
GoogleDNS 8.8.8.8 and 8.8.4.4

[Joshbseen]

Hey thanks for responding. 

That IP address sent the same message of "not connected to router's wifi network." This is on an ethernet connection. 

I tried with both a Google and Cloudflare dns on the pc end.

Is this an ISP issue? I have factory reset before and never, to my memory, had this issue before. I run through Comcast, so just the thought of contacting customer service depresses me. 

[plemans]

Try factory resetting 1 more time. But disconnect the coax cable from the modem. Then push and hold reset for 7-15 seconds while powered on. 

Then try and connect and follow the install guide. 

Try using a windows pc if you're on mac/ios

[Joshbseen]

Yeah I did all that. 

I even contacted the ISP. They did a reset on their end and confirmed the modem/router had no issue from their side.

Established the modem/router has gone into critical failure mode.

Purchased a Nighthawk AC1900 wifi cable modem router and am currently enjoying quite an improvement to internet speeds and functions all around.

Thank you for responding. I posted everywhere and you where pretty much the only one that chimed in.