Redirecting all request to a specific folder, works except for SSL doesn't?

I have a folder on my server called john. Inside this folder is an application I am working on.

I have a self signed cert installed.

if I go to https://mydomain.com/john/signin it works.

I have an .htaccess that redirects all request that don't begin with either the words john or julian to /john:

RewriteCond %{REQUEST_URI} !^/(john|julian).*
RewriteRule ^(.*)$ john/$1 [L]

Now if I go to a non SSL page like http://mydomain.com/about the page http://mydomain.com/john/about is loaded (the URL is not redirected).

However if I go to an ssl page like https://mydomain.com/signin I get a "404 Not found" error.

Any idea what would cause this?