If data does not display correctly
For instance, you've just made some changes, but Facebook keeps posting old information.
1. Make sure you publish the page
after you make changes
2. Go this page https://developers.facebook.com/tools/debug/og/object/
add the link to your website and click "Fetch New Scrape Information".
After you click "Fetch New Scrape Information", Facebook goes back to your page and collects the new data. The cache it had before that gets deleted.