An error occurred during a connection?

Unable to access three sites (so far): MacOS9Lives.com, 68kmla.com and wycokck.com. I keep getting this response: "An error occurred during a connection...". Or in the case of the local city government's website (wycokck.org). I get a message that I am not authorized to access it. All other bookmarks tested here seem to function properly. Google Fiber customer (GFiber) using the Nest Wifi Pro mesh system which reports a "Great" connection via all (3) access points.