I've noticed the dolphins when they try to push an item above after it sinks, they try to do so while sometimes pushing the blocks away from the original spot which can actually give a hard time for the player to find it if the place has many layers which can make the item despawn.

For it was a bug or no I would like to see a solution for it as it can get annoying even if I had no trouble and my building blocks are just pushed away from me.