Sharing on facebook no snippet

Hello, I have on a blog https://mujsalekcaje.cz/blog/ installed plugin Social Sharing Toolkit for sharing to Facebook. But when I press share button, it won’t load the snippet of the post, but will only display string WEBLOGDESCRIPTION.
On the other domain (same hosting, the same version of WP), it works fine) I tried other sharing plugins, but it still does the same problem. Does anybody have any experience with something similar?