Mobs picking up items doesn't explain it, since there have been instances where I died of fall damage or even while I was testing it using /kill, the inventory items would despawn after 5 minutes even when in unloaded chunks while the items that I manually dropped wouldn't, which is the correct behaviour.
Mobs picking up items doesn't explain it, since there have been instances where I died of fall damage or even while I was testing it using /kill, the inventory items would despawn after 5 minutes even when in unloaded chunks while the items that I manually dropped wouldn't, which is the correct behaviour.