My friend was was building a structure in survival when he and I noticed that the TPS in game were very low, probably nearing 1-ish (he found out by trying to eat bread while he was on the roof of the house.) His health was low, so he decided to just kill myself and grab all of his stuff back so he'd have full health and hunger. When he jumped off nothing happened, no animals were moving or anything, and he took no damage, so he just decided to disconnect and reconnect (You can see this the chat log Screenshot).
When he got back into the game, everything was fine, he was still on top of the house he was building, and he had the same hunger and all that he had when he left. But he noticed that all of his stuff was on the ground, including his exp.
He apologizes for not taking a screenshot of this, it didn't cross his mind until he picked up what was on the ground
His entire inventory had been duplicated, I assume as a result of his death at a very awkward moment in time. Every item or piece of armor that had been duplicated kept its original durability (It's what most screenshots are of.) And as far as I was concerned, he left, then died after he was gone, so he didn't exist on the server, but was still able to die...
TLDR: TPS was very low, and my friend tried to die from falling, but he took no damage, so he left the server, and reconnected, only to find he had kept everything on him, but all of his stuff was also on the ground, as if he had died. Upon picking it up none of it disappeared, and they were all perfect duplicated of his entire inventory. Weirder even, for me it said he left the game, THEN died (he died while not ingame.)
Please reply if this still affects 1.16