Замени def update_command_selection на мой. У Меня при зажими все нормально стало показывать.
Код:
 def update_command_selection
    if Input.trigger?(Input::B)
      Sound.play_cancel
    return_scene
    end
    if Input.trigger?(Input::C)
      Sound.play_decision
      @command_window.active = false
      @item_window.active = true
    end
 case @command_window.index
when 0
@item_window.dispose
      @item_window = Window_Item.new(0, 112, 544, 304, @command_window.index)
      when 1
  @item_window.dispose
      @item_window = Window_Item.new(0, 112, 544, 304, @command_window.index)
when 2
  @item_window.dispose
      @item_window = Window_Item.new(0, 112, 544, 304, @command_window.index)
when 3
  @item_window.dispose
      @item_window = Window_Item.new(0, 112, 544, 304, @command_window.index)
      when 4
  @item_window.dispose
      @item_window = Window_Item.new(0, 112, 544, 304, @command_window.index)
     when 5
  @item_window.dispose
      @item_window = Window_Item.new(0, 112, 544, 304, @command_window.index) 
end   
end