Okay, after checked further, it seems like that is your site cache issue.
For example, If you enabled cache and updated that meta data through Metaman and press save.
When you try re-scrape from Facebook debugger tool, it will not show the latest meta data like what you made the changes just now, because your site page already cached.
To work around this, if you updated your meta data, you have to temporary disable this following cache then only re-scrape again from the Facebook debugger tool, you can watch my video here, it work perfectly fine. :
http://take.ms/aUeAh
- Disable this system - cache from global configuration setting (
http://take.ms/FvpRs)
- Disable System - page cache plugin
- Clear the cache from backend