I finally got my ads to serve over https.
I use Javascript to call ads, so I went into the spcjs.php file located in the www/delivery folder.
I went down to line 2355/2356:
$conf = $GLOBALS['_MAX']['CONF'];
return 'https://' . $conf['webpath']['delivery'] . '/' . $file;
and changed it to https, it was originally showing http://
Now it finally works.