When picking up an item off the ground, it is occasionally placed into the "boots" slot, destroying whatever item is there already.

Me and multiple people playing on our server have noticed that on occasion, when picking up an item off of the ground (not entirely sure if this applies to only items, blocks , or both), it will sometimes be placed into the inventory slot meant for boots. If any boots are in the slot, they are destroyed. We aren't 100% sure, but this seems to only happen within the chunk where the original spawn point was. This may happen in other places, however. Like I said, not 100% sure.