Last time I checked Budgie reported itself as GNOME in the XDG_CURRENT_DESKTOP environment variable, so Haguichi would in this case obviously use client side decorations. But maybe this variable has been changed. Can you tell me the result when you execute "env | grep XDG_CURRENT_DESKTOP" inside a terminal on your Budgie desktop?
Last time I checked Budgie reported itself as GNOME in the XDG_CURRENT_DESKTOP environment variable, so Haguichi would in this case obviously use client side decorations. But maybe this variable has been changed. Can you tell me the result when you execute "env | grep XDG_CURRENT_ DESKTOP" inside a terminal on your Budgie desktop?