So I have an update on the issue.
After ruling out all other possibilities listed.
I got on the phone again with the ISP and told them that other internet accounts are working on this system, it is looking like a DNS error to me. One of their techies yesterday told me that there should be no DNS unless I changed something, which I hadn’t.
As it turns out, they had edited their DNS rules to only allow their DNS servers and Google’s. I had another DNS setup in the forwarder that was being blocked and, for some reason, ZS was not using the others at all. I removed the openDNS servers and it began to work fine again.
I grately appreciate your help in troubleshooting this with me, you have been incredibly helpful. I’m sure it would have taken me longer to blame the ISP, I was so stressed out that I was working with blinkers on.