Hi Alex, I have a problem that's really puzzling me. My comments are visible, and others are able to leave comments. One as recent as yesterday.
But when i try to post a comment or a reply i get a message from fb that says I'm not logged in, and to try again. If i go to the comments moderation tool on Facebook i can reply to comments with no problem.
Here is an example page that i can't add or reply to comments.