Flush your DNS you can get the info for that here at this Link
or you can just google Flush DNS and follow the instructions
That isn’t going to help. I used nslookup.io the check resolution to remove my network from the equation.
[Edited by pell, 7/20/2021 8:42:55 AM]
Tried that .still down
Call your ISP, they have the tools to deal with these types of issues, probably need to ask for tier 2 support.