After editing permalink, Facebook cannot generate preview

Hello!
I’ve noticed this problem long ago and it is still in effect. While I write new WP post, permalink is automatically generated from post title (I use nice permalinks: /%category%/%year%/%monthnum%/%day%/%postname%/), that is all fine. But, while still writing this post, if I edit this auto-generated permalink from, say:

http://www.mysite.com/stuff/2014/10/08/autogenerated-ugly-permalink/

to something like:

http://www.mysite.com/stuff/2014/10/08/autogenerated-nice-permalink/

Facebook no longer can generate preview after pasting this new URL in Facebook’s Status text area.

On the other hand, if you copy that old auto-generated permalink and paste it into Facebook, preview generator does it’s magic. With OLD permalink, which is now obsolete.

I repeat – Facebook likes auto-generated old permalink and dislikes new permalink. I also tried to give Facebook an ugly permalink, ie:

http://www.mysite.com/?p=123

But Facebook still does not generate any preview.

Does somebody have a clue about this silly, well, if I may say – BUG?

Thanx in advance.