I'm unable to change the header on a page - please see my 41 second video:
If you need anymore information please let me know.
I think there is a issue with the Advanced Custom Fields PRO plugin, as like the front page panel as well as the header settings panel are created with this plugin. I also need to take a closer look on this one.
The header settings are showing up again, I have described the issue in your other ticket.
I will close this ticket as the issue is solved
If you have any questions feel free to open a new ticket.