Buddypress activity to Facebook turns out wrong

Instead of posting the status update, someting weird is posted:

{\"media\":\"\",\"update_txt\":\"Ein%20Timeline-Beitrag%20von%20paraddicted.net\"}
Activity Update
{\"media\":\"\",\"update_txt\":\"Ein%20Timeline-Beitrag%20von%20paraddicted.net\"}
Netzwerk, Magazin und Verabredungen für Gleitschirmflieger

Am I missing something?

Auto-publishing of posts works.