Yes, I noticed that a bit ago. And you are right, I have not had that issue yet come up but the SSL cert I have does not match that w/o the www it seems.

From a quick search it may be related to the alternative names like https://serverfault.com/questions/738883/ssl-certificate-non-www-not-working points out in the first answer. I believe the certificate request has to have both the www and the non-www listed.

You also, depending on your setup, could use a 300-level HTTP redirect to include the www but that is not at the static HTML level I believe that is at the server level.