Using current Firefox in Ubuntu 24.04/KDE neon unstable and if I download a file the download popup lists it but it can not be dragged anywhere. This does work under X11. The debug output suggests the drag is started: >WAYLAND_DEBUG=1 firefox 2>&1 | grep drag [4076010.323] {Default Queue} wl_registry#2.global(41, "xdg_toplevel_drag_manager_v1", 1) [4076102.074] {Default Queue} wl_registry#28.global(41, "xdg_toplevel_drag_manager_v1", 1) [4076452.357] {Default Queue} wl_registry#45.global(41, "xdg_toplevel_drag_manager_v1", 1) [4076452.739] {Default Queue} wl_registry#47.global(41, "xdg_toplevel_drag_manager_v1", 1) [4076462.345] wl_registry#48.global(41, "xdg_toplevel_drag_manager_v1", 1) [4129970.939] {Default Queue} -> wl_data_device#22.start_drag(wl_data_source#90, wl_surface#87, wl_surface#68, 16826)