Isn't just using CSS position: sticky more simple and more beautiful?
https://css-tricks.com/position-sticky-2/
And for Vue.js guys i advice to take a look at the main and only component to check out how gracefully Vue.js solved this task https://github.com/altrusl/vuesence-sliding-header/blob/mast...
I don't understand why you'd chose an incredibly more complex solution that is objectively worse in nearly every way.
On Android Firefox Preview as well as Kiwi Browser (chromium) I simply see a list without anything sticky.
Same for desktop mode in both Android browsers.
1. Stack two headers on top of each other, both of them sticky. (Only topmost header is visible.)
2. At a certain scroll position, fade/scroll/hide the top header.