SSL not working on subdomain

[sdayman]

Cloudflare’s certs have two entries: example.com and *.example.com
You’re covered at this end. The *.example.com covers www and lab.

Your ‘lab’ subdomain is throwing a 521 error, meaning it’s not responding to Cloudflare’s requests. This can be if Cloudflare SSL is set to Full and your server doesn’t support SSL.

Community Tip - Fixing Error 521: Web server is down

Error Try the suggestions in this Community Tip to help you fix Error 521: Web server is down. Background A 521 error happens when we are unable to make a TCP connection to your origin server. Specifically, Cloudflare tried to connect to your origin server on port 80 or 443, but received a connection refused error. This is often caused by security or firewall software and happens if the origin server has directly refused Cloudflare’s proxy request. [Banner in tip catalog] Quick Fix Ideas …