Sticky header height ignored

I’m trying to use the sticky header. I have it set to 125 height by default, then 60 when scrolling.

However, the top of the page (above the breadcrumb) including the page title is obscured at all times when sticky header is on. When off, it appears below the header, but when on, it’s hidden. You can just about make out part of the title text when scrolling, but only some of it. Why’s this happening?