@Pikabon: I see you have made lots of changes on the ‘Primary Header’ which has caused the changes on structure of header. So please reset the primary header and add menu once again. For this please follow the following steps:
i. Go to your dashboard Appearance => Site Editor
ii. Then you need to click on Patterns => Manage all template parts
iii. You will see lists of template parts, you can find the primary header there.
iv. On the right side of the primary header list there you need to click on the clock icon to reset it.
Below is the screenshot
Thanks
Sujapati