cant load a website

I am a new export agency. I need to be able to use ITC Trade Maps for a business tool. One random day it stopped loading. It will show the page, even say its loading then flash to white screen. I have tried all the tricks i know from a hard reset to changing the DNS. Can anyone advise how or why Xfinity's security won't allow this site to load? I know its the Xfinity Cybersecure because i can turn off the Wifi on the mobile and it loads fine. But not on anything running on the network.