no view / preview for posts on Facebook

Recently, my posts (new but also older ones I shared earlier) are not visible any more on Facebook when I try to share them. The last post I shared was on january 9, somewhere after that it stopped working: that is: I can only see the name of my site and the link on it links to the right post on my site, but the image and summary do not show up, so there’s no telling what de shared post is about.

I can’t see shared events either (plugin The Events Calendar), but regular pages and post/pages from plugin TotalTeam seem to show up like they should (like [ redundant link removed ]).

I tried everything I could think of: disabled plugins, changed theme, delete cache, scrape url, checked setting for plugin Yoast, deactivated all plugins that were added or updated after jan.9. I tried other browsers, other devices. Sharing through the sharing icons or pasting the url in Facebook. Nothing solved the problem.

I’m getting quite desperate, so I really, really hope someone can help me out on this!

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