Webpages NOT SECURE- keeps getting me back to XFINITY ACTIVATION page on websites

Xfinity please help me.  I am a new customer and I have a complete connection to the internet, streaming fine, zoom video conference fine, HOWEVER I am unable to visit SEVERAL websites as I am getting NOT SECURE messages from websites such as walmart.com, salesforce.com, posterenvy.com

 

It keeps directing me to ACTIVATE my XFINITY Account when i land on some of these websites.  Also, I will sometimes get a a normal landing page but when I have to login I am unable to do so because xfinitiy says it's unsecure.

 

I have tried 3 different devices (iphone and 2 computers) and 3 different browsers (IE, Chrome, and Safari).

 

I started a new job this week and cannot perform the functions of my job as I am unable to visit several websites due to this error.

 

I have called xfinity several times and they are unable to help me.  

 

PLEASE PLEASE PLEASE HELP.

 

Kevin