You can add the following code in your theme’s functions.php file, or in a functionality plugin, to allow Photon to cache your images served over HTTPS:
add_filter( 'jetpack_photon_reject_https', '__return_false' );
It didn’t work! 🙁
I tried both options you offered. I added that to theme’s function.php and that plugin. No one worked and images are still serving as http for the visitors.
Could you post your site URL here, so I can have a look?
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http://jetpack.me/contact-support/
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