Problem accessing web pages using MacOS 10.14.6

In the last week or so I've started getting the following message when trying to access websites: Access "Denied

You don't have permission to access "http://www.kbb.com/" on this server.

Reference #18.bf254b8.1571800881.9373a5"

Since this is a commercial site, I can't figure out why I can't access it. This also occurs on other sites and on my IOS devices. The only things that are relatively new is that Apple erased my disk and reinstalled the OS about a week ago and I added a VPN (ExpressVPN) to my system recently.

Lynda Cook

Mac 27" late 2015, OS 10.14.6