Scrolling the room list with gestures doesn't reproduce this. It only happens when scrolling the room list by dragging the scrollbar quickly. This feels like a bug in SwiftUI's layout logic; it's marking both the Room List and the Avatar-only room list as dirty during scroll and rerendering both, then the toggle that hides the avatar list fires and we see the remants of the animation.
Scrolling the room list with gestures doesn't reproduce this. It only happens when scrolling the room list by dragging the scrollbar quickly. This feels like a bug in SwiftUI's layout logic; it's marking both the Room List and the Avatar-only room list as dirty during scroll and rerendering both, then the toggle that hides the avatar list fires and we see the remants of the animation.