Board Thread:Support Requests - Getting Technical/@comment-3319977-20180816052440/@comment-168424-20180817195104

Yeah, this issue is based on a limitation of subdomain matching on SSL certificates. Basically certificates don't generally handle sub-sub domains (i.e. subsub.something.wikia.com). One route is to used a dash insead of the first dot (i.e. subsub-something.wikia.com), but there really isn't a good solution, so consistency matters more.

This article explains how a company might go about getting certificates for a sub-sub domain, but if you consider how many thousands of wikis FANDOM has to service, it isn't really feasible.