SSL on Primary Domain Working But Not Working on Sub Domains

Website, Application, Performance Security
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30

You shouldn’t use www on a subdomain. It should only be sub.example.com

  1. That’s not something I see mainstream sites do.
  2. Cloudflare’s TLS certificates only cover example.com and *.example.com (not ..example.com)

So…can your browser reach sub.example.com?