Spectrum analyzer

I have an arris sb8200 modem.

Of course I can see my modem status page by using:

192.168.0.1  or 192.168.100.1

But it doesn't show 4 of my upstream channels.

I saw online that you could view your spectrum analyzer by going to:

192.168.0.1:8080 or 192.168.100.1:8080.

Neither of them work. Any idea why?