Please see the attached screenshot below. You don't need the red marked area. Please remove it. You can edit the column visibility from column options. Example: if you want to hide "Menu-Right" in tablet & mobile devices, you can go to column options -> responsive area and toggle the phone, tablet buttons.
I tried to edit the layout but it does not save and gives a error - see in the screenshot below.
The menu inside the header will work fine once you remove the red marked area from layout. Now the header row is hidden on mobile & tablet.
You need to disable these three toggole buttons:
Please do let me know if that works.