Make sure you have configured your site's configuration.php file so that the live site url also includes https:// from the setting in that file. That is what is used across a Joomla site to determine the url of css and js files.
And how do you do that? I'm having the same issue .
I put this in for live site in my configuration.php and it's still blocking content from the template.
public $live_site = 'https://';