background image for header isn’t rendered properly

for chromium based browser, the background image for the header will not render properly on load.

Initially, I thought it’s issue with my setting, but turns out it’s broken as well on the live demo provided by the theme creator. Have to scroll in order to see the correct rendered image.

If I log into the admin console, it works just fine. But the sec I log off, it’s broken.

No issue with firefox thoguh.