Wow, Mike, thank you very much for the research. I thought it would bei something within the theme and thus some css to change. I did not want to cause such a lot of work for you. Thanks, I will check those sources out!

I can do certain customizations by myself, but am confused because of the different files that generate menus and not sure which files have to be touched for this menu especially.
But it’s okay, I will find out.

Hi Ismael,
Thank you for getting back to me.

Yes, I tried the custom menu widget, that is what you see left at the bottom in the screenshot. That is exactly what I want to get – functionwise – but with the standard menu.

Because it’s the main navigation of the site I am talking about, there is no use, from my point of view, to use the menu widget, because I would then have two menus and need to remove the standard main menu from the sidebar. Also I still need the regular menu on the mobile versions.

Just for clarification: I am using the photography demo that has the header on the left side. So the header on the left side contains the main menu automatically. There is no need to add a sidebar widget, because the menu is already there.

I only need to know which files to alter to reduce the sidebar effects to a very simple menu with the submenu showing below the main level menu item on click and not on hover at the right side of the main menu item.

So, this is what I would like to achieve: Click on a main menu level item A opens the page A as well as the submenu A. Submenu A stays open as long as the page A is open or one of it’s subpages.
Submenu A appears below main menu level item A and pushes the other menu items down.

I hope this makes it clearer.
Thanks,
TiniP

I tried different browsers and cleared the caches of all browsers a few times. It’s on desktop browsers chrome, firefox, safari (mac), not on touch devices. Please see screenshots in Private Content.

I forgot to write: Just click on one of the brands on the home page.
Thanks

Thanks for getting be to me so fast, Yigit!
Unfortunately the site is still local.

The code that was recommended in the post was made for changes in the sidebar widgets. I would need this for the footer widgets. I tried to change it with the use of information in the registered-widget-area.php of the parent theme, but no luck.

function ava_remove_some_widgets(){
	unregister_sidebar( 'av_everywhere' );

    register_sidebar(array(
    	'name' => 'Displayed Everywhere',
    	'before_widget' => '<section id="%1$s" class="widget clearfix %2$s">',
    	'after_widget' => '<span class="seperator extralight-border"></span></section>',
    	'before_title' => '<h2 class="widgettitle">',
    	'after_title' => '</h2>',
    	'id'=>'av_everywhere'
    ));
}
add_action( 'widgets_init', 'ava_remove_some_widgets', 11 );