Clicks along the top reach a fullscreen window
A change merged into quattro drops the bar's input region while the active workspace on that screen has a real fullscreen window. A maximized window keeps a working bar.
Over a fullscreen window, clicks along the top edge went to the faded-out bar instead of the window, so controls there could not be clicked.
Hyprland 0.56 lets the pointer through a faded top layer only while it holds that layer below fullscreen, and the flag is per monitor. Any window on another workspace leaving fullscreen lifts every layer back above, and the invisible bar strip takes the clicks. The bar refreshes Hyprland's toplevels on fullscreen events.
David Heinemeier Hansson checked it live. With Hyprland in the bad state, a fullscreen probe window received no pointer events along the top before the change and did after it. With no fullscreen window, the bar still took input over a window under it.