Pull the weeds out of your Cloudflare setup.
Putting a self-managed WordPress server behind Cloudflare: origin lockdown, DNS, caching, the WAF, Tunnels and the errors you hit along the way. Every guide shows the date we tested it.
Chrome shows this when your DNS works but gave no address for this one name. Open the same address on mobile data. If it fails there too, the problem ...
Chrome's HTTP/3 runs on QUIC, which uses UDP, and ERR_QUIC_PROTOCOL_ERROR means something on the way blocked, cut off or damaged those packets. On a s...