A 2x2 Hopper system all leading into one chest (Image attached)
Had some chickens on top so eggs could be put into chest automatically. Waited until one laid an egg and checked the chest and it had 3 stacks and was still filling up.
I got rid of the chickens and emptied everything out. I then threw just one egg into the top of the hoppers. It got sucked up by a hopper, and the chest had 15 and stopped there. One more egg onto the top, it stayed there and the chest kept on filling up.
I Clear everything out again, I throw my slightly damaged sword on top, It doesnt get sucked up and the chest fills up with the exact same sword.
It looks like the game mode doesn't affect this glitch from my testing.