postmodernTIL if you run gnome-terminal under Xorg it will default to always enabling GNOME's annoying Client-Side Decorations (aka header bar) instead of using the Window Manager's own window decorations. However, if you run the Window Manager under Wayland, even via the xwayland emulation layer, gnome-terminal is smart enough to realize it's not running under gnome-shell and disable it's silly Client-Side Decorations and not disable the Window Manager's window decorations.