When I first log into xfinity and open up my email account all is fine. But within the first or second email that I view, from then on in the url line it indicates "Not secure https..." Why is that?
Try resetting the site settings for the site in your browser preferences. I'm using Chrome and to the left of the "https" is a small circle with an "i" in it. If I click on that it shows the settings for the site and has the option to reset them to the defaults. Mine also said not secure and resetting it fixed it.