Shortcodes don't work in Posts

Hi Folks,

I tried to use shortcodes in posts for my new project (look here) But the won’t work. Although they do work on my pages…

I tried different shortcodes for different Plugin and tried to wirte them in ‘Visual’ as well as in ‘Text’. But nothing works…

What am I doing wrong?

Is there maybe something I’ve to add to my funcions.php to make them work?
I wrote the theme myself and maybe there or somewhere else is something necessary missing…

Has anyone an idea what might be wrong?

Your help is truly appreciated!

Cheers,
-colo