Item summoned with that command :
/summon Item ~ ~-5 ~ {Item:{id:clock,Count:1},Age:15}
didn't despawn after 15 games tics, and it doesn't work for any Age and any item.
Steps :
• Take a command_block
• Write inside [ /summon Item ~5 ~ ~ {Item:{Count:1},Age:20}
• What should happen : It should despawn after one second.
• What happened for me and may happen for you : It won't despawn until 5 mins.
I hope i did everything good and this is a real bug, and sorry if i made you loosing your time (and sorry for the grammar i am french 😉 )
Items despawn when Age is 6000, not 0. The value counts up, not down. To make an item despawn in 1 second, set Age to 5980.