Item entities can be picked up even if the entity trying to pick them up is not the owner if the Age value is >= 5800. Expected would be that there is no such special condition and items with an owner can never be picked up by a different entity.
The following steps require that your UUID is not 00000000-0000-007b-0000-00000000007b (Most: 123L, Least: 123L)
- Summon an item with an Age of 0
→ You cannot pick up the item
- Summon an item with an Age >= 5800
→ You can pick up the item
Based on 1.12.2 decompiled using MCP 9.40