May be I do not understand.
On your blog page below
Blog – IW-Nordharz Blog (iw-nordharz-blog.de)
The post “Best of forum” with the double dotted line IS STILL a sticky posts.
If you have removed the sticky post option, then try Clearing ALL your caches.
If you are speaking of a different post, be more specific with a link to the page showing it and the title of the post