WordPress preview not showing in Facebook

Suddenly, when posting a link from my site in Facebook, only the site name is displayed. No post title or featured image. I have been posting successfully for a few years from this site, and suddenly it has stopped working. I have no caching or SEO plugins installed. The first time it happened, i was able to click off Standard under Format and the problem was fixed. Now it doesn’t work anymore. The only thing that updated, I believe, was the WordPress install. Could that have created the problem? If so, how to fix it?

The page I need help with: [log in to see the link]