Ok, thats maybe the reason.
I know the hidden menu and used it on different sites
Thank you for the golden hint!!!

Hello

It sounds like the news articles that you are linking to do not have their own menu items, they, therefore, inherit the modules of the homepage. To resolve you will need to create a hidden menu and item for your articles. This will allow you to assign/un-assign the modules of your choice to these articles via the menu item.

A quick search on 'joomla hidden menu' will give you some further information if required.

Hidden menus in Joomla can be 'tricky' so often a much easier solution would be to install an extension like Advanced Module Manager (https://www.regularlabs.com/extensions/advancedmodulemanager) which offers you a lot more control regarding your module assignment.

Ciaran

You are soooo smart
Thank you!

Any suggestion for the second problem?

Hello

You will need to remove the space between 'url (' which is making your CSS invalid. Also use the full URL to your image (in.c http)...

#container_header {

    background-image: url('http://web92.burns.kundenserver42.de/mess2020/images/messerich/header_bg1.png');

}

Ciaran

I also have a problem with the news Modul on top.
When i click on a picture (damen, herren or sport) the complete homepage will load again, with the article in the content area instead to open the article in its own page.

Hi Ciaran,

the css ist active like you wrote in your first awnser.

http://web92.burns.kundenserver42.de/mess2020

Hello

Would you have a URL to an example of your header?

Ciaran

hello,

sorry but that didnt work.
I have tryed it also with !important and z-index, but nothing.

Hello

To amend try adding the following to the Custom CSS field of your templates parameters (Extensions -> Templates -> [YourTemplateStyle] -> Custom CSS)....

Replace the URL with that of your image.

#container_header {

    background-image: url('https://joomla51.com/images/header_surf.jpg');

}

Ciaran