When logged in and scrolling down past a certain point, a sticky header annoyingly appears and takes up vertical screen real estate. Since all of those UI elements are available by scrolling up this seems like more of an annoyance than anything, especially for people using large font sizes on wide aspect ratio screens.
To disable, go to Preferences -> Appearance
and click Custom CSS
next to Vector (2022)
. Then save the following to the new page:
.client-js.vector-sticky-header-enabled .vector-sticky-header {
display: none !important;
}