I realized that the meta information for Facebook are only used if I share a page with Safari (share button on my website for example here: http://www.issdichfit.ch/index.php/fragen/machen-kohlenhydrate-am-abend-dick
). Chrome and Firefox don't respect the meta information.
I updated the meta information yesterday and tried to share the same post yesterday. As I had to change the meta image for Facebook the old information was still in the cache somewhere so I had to wait. Today morning I tried to share the post (mentioned above) with chrome using the share button on my page. On Chrome my default logo and wrong meta information showed up in the preview (small pop up). In Safari everything worked fine.
Share the page in a new status update within Facebook by copy & paste the URL seems to work correctly. Have you ever experienced such a behaviour so far?
Kind regards, Stefan