SSL – Connection not secure

With a site delivered over SSL with a valid certificate in maintenance mode –
Chrome provides the warning: “Your connection to this site is not fully secure” “Attackers may be able to see the images you’re looking at on this site and trick you by modifying them”

This message appears to be caused by the media content on the maintenance page being served via http rather than https. Included CSS and JS scripts use the proper URI (https), however any media uses http.

such as content in
/wp-content/plugins/site-offline/assets/img
&
/wp-content/uploads/

Disabling maintenance mode resolves the error.

Not a big deal as we don’t expect users to need to enter personal info on the Maintenance landing page.