Transparent menu background on all pages

Hi there,

I'm having trouble working out why my header menu isn't working, on the main page it is a normally (header with transparent background overlaying my hero section).

But when ever i go to a different page instead over overlaying the first section it is above it, thuse leaving the header background white.

From what i can work out it's not because of the section because even if i copy in the hero from the home page it still doesn't overlay.