Cannot insert items into the top slot of furnace

In survival mode, items in the inventory side of the furnace ui are only items that can be inserted into the fuel slot of the furnace. Even if there are items in the inventory that can be inputted into the top slot of the furnace, it will not appear in the furnace ui. (Note - this bug report is for 0.13.0 beta 5, but it was not a choice in the version list above.)