Comparator doesn't update with Hoppers, Dispensers, etc

When items are deposited into a Dispenser, Dropper, Furnace or Hopper manually or by
Hopper(s)/Minecart Hopper(s), if a Comparator output is attempted to be taken, it will not update automatically. This however does not affect chests or locked chests as shown below. I experimented this bug by placing one item into inventory blocks and attempting to withdraw a comparator output.