If you double click on any slot in the furnace the progress bar and energy bar disappear if neither of them get updated by the server. If an update occurs they reappear. If the furnace is being updated and you double click you can see the GUI elements flicker.
If you double click on any slot in the furnace the progress bar and energy bar disappear if neither of them get updated by the server. If an update occurs they reappear. If the furnace is being updated and you double click you can see the GUI elements flicker.