Safari cannot open page because server stopped responding

“server stopped responding” indicates the problem is at the other end of the connection, the website or page you are trying to access. Have you tried getting there on another device, computer, iPhone, etc?

Do you know what Private Relay and is it enabled on your device and the others you tried? Private Relay is Apple’s version of a sort of mini VPN that hides your IP address. You do have to be a subscriber of iCloud+, however.

Any of that the case?

Are all of the devices tested on the same network, such your home WiFi network. Does your WiFi router have a firewall active? Your symptoms all point to some kind of network problem, not Safari in particular.