Persistent ERR _SSL _VERSION _OR _CIPHER _MISMATCH Error with Certificate

Currently your site loads fine, so the 502 may have been an intermittent problem.

There were actually quite a few issues, you had no SSL certificate, your DNSSEC configuration was incorrect, and the proxy certificate was not issued.

Simply wait until your registry really dropped DNSSEC. You can check that at DNS Checker - DNS Check Propagation Tool