multiple domains for same app

I am attempting to set up SSL certificates on my domain using letsencrypt_webfaction. I had this all working, then I went on vacation and my server was migrated. Now everything is bananas and I can’t sort it out. Anyway, my attempted set-up:

I have one application for serving content: mbserver I have two domains: foo.webfactional.com and secure.foo.webfactional.com

In my Websites pane, I have two set up: - mbsite (HTTP) serves mbserver app for: http://foo.webfactional.com and http://secure.foo.webfactional.com - mbsite_secure (HTTPS) serves mbserver app for: https://foo.webfactional.com and https://secure.foo.webfactional.com

(yes, I know that http://secure... isn’t actually at all secure.)

I can curl http://foo.webfactional.com, but http://secure.foo.webfactional.com fails (It gives me WebFaction’s default “Coming soon” page). I think for the scope of this question, it’s likely the existence of mbsite_secure can be ignored, but I’m including it for completeness.

This honestly seems like the easiest part of the whole process, so I’m a bit beside myself. Please help! Any thoughts about what I might be doing wrong?