Ok now it is working , but now i have the same problem as in xf1
the first time I want to share a thread to fb, no picture will be shown.
only when I cancel this and click on share again a picture will be shown. in xf1 I could only fix this with an add-on.
when i click first time
Unfortunately these are all just internal to Facebook (if you're not specifying a metadata logo in style properties). We don't have any control over the images they pick and how their asynchronous loading works.