Hi @palingenesie,
Thanks for using WP Socializer. You have a nice website and WP Socializer looks good there.
Regarding the issue this is a known behavior. Facebook recently stopped giving developers the share/like count when it is less than 100. This number is not fixed though. It is simply that when the count is high they send it back or else they return 0.
Please find the explanation from Facebook support here – https://developers.facebook.com/support/bugs/318897266426699/?comment_id=323684205948005
Plugin developers have no control over this, so WP Socializer started showing icon instead of 0. Going forward social network websites will slowly deprecate share counts.
Thanks,
Aakash