Dropdow menu in the navbar that doesn't go the right way on the preview mode


I really have trouble with my navbar.
In desktop and tablet mode it is ok, but on mobile (landscape and portrait), where I have a drop down menu… this is not working like I want.
I may have made a mistake when I created the navbar… but I can’t fix it, I just don’t have enough skills ! Can someone help me please ?

Just to make myself clear, here is my navbar in desktop and tablet mode :

Here is my navbar with the dropdown menu hiden in mobile landscape mode :

What I designed for the opened drop down menu :

What it does in preview mode :

After all, I’d like to do something easier, like that :

But my problem is that I couldn’t even go back to this easier version… And I am worried that I have to start again my navbar… I really don’t want to… :sob:
Maybe the problem is that my “company name block” is in the middle of the nav menus ? I don’t know…

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

You are welcome to poke around one of my menus to see how itʻs set up!