Modals persist scroll position, background image problem

[peterlunglum]

I have multiple modals on my site. Each has a top header image contained. When scrolling on mobile, the modal persists its scroll position within. I close and scroll through my site and everything works fine, but when I go back to the original opened modal, the background image disappears/is gone. I think this has to do with positioning. Any ideas on why this might be happening?