Modem diagnostics page

I have an Arris TM822 telephony modem that I have rented from Comcast for years. Was always able to acces the diagnostics page at 192.168.100.1 for years until recently. I have a Windows 10 computer and tried both Chrome and Edge to access the page and in both browsers I now get the "danger connection not private screen" warning about possible hackers if I continue. I have cleared cookies and history,. Windows is up to date. I have run a manual scan with Defender and Malwarebytes and I get nothing. Otherwise everything else runs fine. I am  very cautious on the web and do not download movies , music etc. Keep my browsers updated religiously. Have read that it has to do with this being http vs.https . How do I securely access my modem if the browsers are blocking this page because they can't verify the security certificate. Have run  windows troubleshooters and everything comes up good. Otherwise everything else works normally.