PenciDesign replied
Hi,
Since you're using a child theme, you need to backup your changes on the current header.php file.
After that, copy all the codes from the header.php file from the parent theme of the latest version and paste it to the header.php file from the child theme - then add your changes back. It should be work fine.
BUT: I recommend you add custom code to the header.php file via Customize > Logo & Header > General > "Add Custom Code Inside <head> Tag" or "Add Custom Code After <body> Tag" - you don't need to override header.php file from the child theme to do that.
Best Regards,
PenciDesign