You might notice that you are missing your Facebook comments once you switch to HTTPS from serving your site initially on HTTP. The problem is with Facebook not linking the old URLs with the new ones, which is why you might have to do some additional work in order to have your comments back.

It’s important to notice that you’ll still have your Facebook comments form and you might even have some new comments there from after you switched to using SSL, but the old ones from before that would be gone. Not irreversibly, though.

Here is the solution I found in a couple of WordPress.org Forum threads. It worked great for me:

  1. Install and activate Really Simple SSL plugin (https://wordpress.org/plugins/really-simple-ssl/);
  2. See if your dashboard breaks. It did on one of my sites due to some weird environment edge case.
  3. Add a custom replacement for HTML attributes that would contain  the address of the website with HTTPS, instead of HTTP:
Oh, it’s usually the same problem with Facebook likes, so don’t worry that much if all of a sudden you lost all your Facebook like stats on your like buttons in the site. Same solution should fix this too.