Why Does a Website Subdomain Resolve but Show a Certificate Warning?

DNS can correctly point a subdomain to a server even when the certificate does not cover that hostname or the server presents a default certificate.

What to check

Check the exact hostname, certificate subject names, server binding, SNI, chain, redirect target, and whether a proxy terminates TLS elsewhere.

Recommended next step

Issue or bind a certificate for the intended hostname and test HTTPS from a clean client. Informatix Systems can troubleshoot DNS and web security.