In Minecraft 1.21.3 and earlier, picking an item (the 'Pick Block' key binding) simply transferred the item from different slots in the inventory without a special animation. However, now, the picked item will always show the pickup animation, even though the item was already in the player's inventory.

The expected behavior is to continue the behavior of Minecraft 1.21.3, where no pickup animation plays. I believe this is a valid issue as it represents a regression in how the pick item functionality behaves.