Cannot access 192.168.1.254 to log in to gateway modem

from the beginning...

We are on Fibre. A few days ago our TV service went out. I tried all the on-screen suggestions, and power cycling the Actiontec T3200M gateway modem/router seemed to work, the TV service began to work. Then the next day it happened two more times. It seemed to me like a TV transmission issue as my internet was still working while the TV was not. A call to tech support, the agent said he could see an error, but he didn't know what the error was. I once again power cycled the T3200M but that didn't fix it. There is another device (Nokia - ONT perhaps) so I power cycled that and the T3200M at the same time, and the TV began to work again.

Now my current main concern; thinking about the support agent saying there was an unknown error, I thought I'd log in to the gateway modem (as I have done many times, before and after the fibre connection was installed) to take a look around. To my surprise I cannot connect to the login page. I have tried multiple different devices and multiple different browsers, and the most I can get is a red box next to the URL in the address bar that says 'NOT SECURE'. There is no option to bypass and connect anyway. So now I'm wondering if perhaps the Actiontec T3200M is on the way out or perhaps it was something the service agent did that is not allowing connection.

Any ideas on what to do from here would be greatly appreciated.