Step by step i did these
Create a new Facebook App (App ID: 544557495732050)
Create a new Facebook Page (https://www.facebook.com/Pasha-electronic-502844156580479/)
- In App which created by step 1 check yes (Yes, mirror to page - which created on step 2) https://developers.facebook.com/tools/comments
- Create a new web page (which include javascript src and div tag) http://pasha-k.az/ramin/test.html
- Share this link on Facebook Page which created by step 2 https://www.facebook.com/Pasha-electronic-502844156580479/)
Problem: I see different comments. Comment mirroring does not work.
Checklist:
Your FB app status is "This app is public and available to all users" https://developers.facebook.com/apps/
Your FB page status is "Page is visible to everyone" in page's Settings > Country Restrictions
Your FB page status is "Page is shown to everyone" in page's Settings > Age Restrictions
Your URL points to the right page on your website
Your webpage has this META tag:
<meta property="fb:app_id" content="YOUR_APP_ID" />
The META tag above has attribute property= instead of standard name=
There are no curly braces {} around your APP ID in the META tag.
You enabled mirroring and selected your page in Moderation Tool https://developers.facebook.com/tools/comments/
There is no extra extra slash / in your url
You posted the exact URL in your FB page, as the page administrator
On top of your post you see an Earth icon; move your mouse over and you see "Public"
When you comment on your webpage, you see this note under the comment area: "Your comment may also appear on XYZ's Facebook Page."
When you comment your FB post, you see this note under the comment area: "This comment will also be posted to www.sample.com."
You can fix errors using the FB Sharing Debugger https://developers.facebook.com/tools/debug/
You can clear FB sharing cache associated with your url https://developers.facebook.com/tools/debug/sharing/batch/
Workarounds:
Append # at the end of your URL
Try your URL without www
Bug Report:
You can submit a bug report to Facebook for Developer page https://developers.facebook.com/bugs
Notes:
Comment mirroring takes effect on new webpages created after the setting has been enabled. The first you time share the URL, current mirroring status is retained for that URL - forever.
From 6th Feb 2018 Facebook comments mirroring is deprecated and no longer supported.
Comment Mirroring: Pages that currently have Comment Mirroring enabled will continue to mirror comments for the next 90 days. Full deprecation of Comment Mirroring will conclude on 2/6/2018. Comment Mirroring is no longer available for Pages that do not have it enabled already.
https://developers.facebook.com/blog/post/2017/11/07/changes-developer-offerings/
来源：https://stackoverflow.com/questions/38688599/facebook-comments-mirroring-doesnt-work