Sorry for late reply. We missed your topic.
It seems that bootstrap CSS is conflicting the main theme CSS please go to Appearance -> Customize/Theme Options -> Design Options Tab -> Custom CSS paste the following CSS code and Click on save button:
#access a {
-webkit-box-sizing: inherit;
-moz-box-sizing: inherit;
box-sizing: inherit;
}
The Code don’t works. So i disable the bootstrap Plugin. But now i have a new Problem … can you look at it?
Now theres the post image always under the regular header image. why? i want the post Image only at the post (like the other posts following the first posts) http://csu-new-wahl.de/aktuelles/
You are using slider not a header image. If you would like to disable that image you can disable the slider or remove the post id from the slider settings from customizer.
However, If you want to exclude the slider post from your blog. You can also set that via slider settings via customizer.