Sub Menue not sticking after saving

Hi all,

I am getting a little frustrated (also have to say I am a WP beginner, but think this is a little more than just a beginner mistake … or at least I hope 🙂 ).

If I create a custom menu I also want to add a sub-menu-item. Hence, I go to Appearence –> Menus, create a new menu, add the 2 pages I have, drag the sub-menu-item under the main-menu-item and push save. Unfortunately, the sub-menu-item is after saving again back to being a main menu item.

Before saving it looks like this:
Main-menue-item
(indent) Sub-menu-item

After saving it looks like this:
Main-menue-item
Sub-menu-item

This cannot be related to any theme, plugin or anything else. I had this with 3 sites, the last I checked is a completely new site: http://culiamsterdam.nl
It has the default theme ‘TwentyFour’ which allows for sub-menu-items and I have done nothing else with the side before – no plug ins, no nothing

Well, now I read quite extensively in this blog, looked videos of how you drag-and-drop and push save (just to be safe I know how to drag and drop and save – you never know how stupid you can be from time to time) and also found a post with the same problem. In there it said to go to the header.php of the theme to change the depth which I did as well.

Now the problem is, I still don’t have a sub-menu which I desperately want. Please, can anybody help?

Thanks a ton in advance.

Best,

Marc