[Theme Horse Support Team]

Hi Grafixer,
You once just activate the parent theme and check whether the header image is displayed or not ? There may be some issue while unhook the functions. I am also surprised how your header image is lost. Just active a child theme and then upload the header image. Hope after doing it you may get it. Did you added some css inside custom css, If yes then add the same css inside your child cusom css section.

Thank you!