When I fire a crossbow, it still shows that the arrow is loaded in the crossbow when it is not. And you can see in your hand that the crossbow does not have an arrow in it(because the arrow was fired) but your hotbar still shows that an arrow is loaded in the crossbow

1 get a crossbow and load it with an arrow

2 fire the arrow

3 the crossbow in your hotbar stays with the arrow in it 

See how the arrow is fired but the crossbow in your hotbar still shows that your crossbow is loaded