Embedded Instragram post doesn't load.

I think this answer might be helpful: https://stackoverflow.com/a/55414214

For the record, changing the embed code's script tag from:
<script async src="//www.instagram.com/embed.js"></script>

to
<script async src="https:///www.instagram.com/embed.js></script>

...does not fix the issue either.

Other services do this somehow:
e.g. "Mailer Lite"
https://www.mailerlite.com/blog/social-media-posts-in-email

Please let me know when this is fixed.