Nvidia has some real DNS issues at times.

I have a couple of Nvidia based PC's and when I go into GeForce Experience to update drivers, it asks me to authenticate my email.
Any browser I use, regardless of settings, fails. Flushdns does not resolve the issue.

My solution:

Open a VPN session (new IP) or use Tor Browser.

Paste the authentication Link in the email which you have received in there.

You should be able to pass the authentication now.

Hope this helps someone.