when you have a spyglass in your ofhand, then zoom and swich from an empty slot to a slot with a loaded crossbow in it wil rezolve in your spyglass floating without you holding it.

this works both in single player and multi player.

I think this bug has to do with the animation you have when holding a loaded crossbow, because this does not heapon when holding any other item or even an unloaded crossbow.

this bug is not game play limiting.