I think I figured it out. I have the [https://addons.mozilla.org/en-US/firefox/addon/cookiebro/ Cookiebro - Cookie Manager] addon. It allows you to establish a cookies whitelist, and a blacklist. I didn't have any blacklisted sites. You can export and import those settings. I was creating a fresh profile. I imported the settings. After that, I tried to login to Github, and here, but I was refused. After some trial and error, I found that, the whitelisted sites ended up in the blacklist. I have know no idea how. Maybe some type of corruption happened when It last exported it. A checked in a couple other earlier backup profiles, and they had no blacklisted sites in those settings CNN and the other mo longer now load up and login normally.