One thing you can also do to verify SSL is fully operational - do the discobot tutorial with a new user and go until the certificate is rendered. If that SVG rendering fails, this is most likely an SSL error then, meaning to say that Ruby’s SSL verification failed.
I had that once when I didn’t have OCSP configured in Nginx.
https://monitoring-portal.org/t/new-platform-work-in-progress/51/20?u=dnsmichi