Incorrect Facebook shares count

Since few days ago I am seeing different number of shares of some of my posts on my Facebook page and in your plugin.

See number of shares on this post:
https://www.facebook.com/IslamOnline.sk/posts/10154362478832629
And the same one on the page:
http://www.islamonline.sk/2016/08/nikoli-radikalni-islamista-ale-frustrovany-neonacista-nove-skutecnosti-o-mnichovskem-strelci/

Any idea what is going on?

https://wordpress.org/plugins/mashsharer/