Items despawning in less than 5 minutes after death in multiplayer

Two players just lost their items to what I'm assuming is this on our server. 1.14.1

They both died, at different times:

First player died at his base and saw the items still on the ground, but could not pick them up. They then despawned after some time. Could not interact with the items using hoppers either.

Second player died and ran back through the nether to find the xp still on the ground, but no items. Xp could not be picked up.

Huh, that's odd behavior. Was that a dedicated server, or realms? If everyone's experienced this on realms, then that does indicate that it could be a realms-specific issue... Also, when the Xp was on the ground, would it still attempt to move towards players? Or did it just ignore them completely?

Dedicated server, although it is running spigot, so I cannot guarantee it's an issue with vanilla, nor that this is valid information for this particular bug. I believe it did not try to move towards the player, as if it was just a graphical glitch.

Current working hypothesis is that the items despawn for whatever reason, possibly a delayed second explosion from a creeper, yet still remain visible to the player.

As of September 15th 2019 in version 1.14.4 this issue is still a problem. 
Currently running a Java server with Paper and  just watched as my friend dropped my pick axe only to have it despawn as it hit the ground. Also had an issue where lag knocked me off the edge in the Nether, causing me to die outside my portal, I came back in under 40 seconds, to my items being gone but the XP still being there.
Another time it was during the Wither Fight. He died, dropped the Nether Star, I died from the lingering poison, came back in less than 2 minutes to my items despawned, but the XP was still there as well as the Nether Star. It's getting very frustrating. These are just a small number of accounts. I had to add a plugin with Player Graves in order to combat this issue.

@@unknown: Paper isn't vanilla, and makes a number of deviations from vanilla behavior (even without plugins). While I doubt they change item despawns, it occurring on paper isn't really sufficient for reproducing here (since this tracker is for vanilla).

@Pokechu22 I should have said we installed Paper because we were told to use Paper to help the issue, this was via Apex staff. That was an oversight on my part.  However, The problem disappeared this morning for our server. No changes made, it just no longer seems to be an issue. 

Just happened to my friends on our Minehut survival server, the both died in the nether, got back in under a minute to find all of their items gone.

Happened to me on a vanilla server on version 1.16.5. In a way to short time all my items despawned. Guess now its rather Math.random() than 5 mins.

It has been happening to me all day long on a Realm. I die and come back to see most of my items gone. I was in the end and when I got to where I died everything was gone, but XP from shulkers I had killed before I died was still there. Mojang has to fix this because it makes playing Minecraft extremely frustrating.

Exact same thing happened to me and friends today. One of my friends died in a cave, I saw her stuff and even picked up a bit of it. A few seconds later, I also died in said cave (no creepers or anything in sight, so the items couldn't have been destroyed). My other friend was there immediately to pick up my stuff, however over 90% of it was just gone. I was back in less than a minute and sure enough, my stuff (along with my friends stuff) was just gone.

This was on a server that I had set up for just my friends and I. It looks like that's the common issue here, right? From the other comments, it looks like this bug is consistently happening on servers/realms.

(1.16.5 btw)

If some of the items were still there, then I'm pretty sure it's not the same bug.

just happened to my friend in a 1.17 server. My friend died and went all the way back to their spawn far away. I wanted to help them but was too late, and saw their items drop. Looking away for one moment to fight pillagers, my friend's items despawned suddenly, would say 30 seconds after their death.

My guess: Me loading the chunk where my friend's items were must've affected the item timer somehow. 

Just happened to me on 1.17.1 vanilla died in nether and 2 min later I arrive at corpse and no items.

Nobody else is in the nether and I was only person online

Just happened to me in single player in 1.17.1 vanilla - had a trident despawn after about a minute and a half.

Just happened to me on a Vanilla SMP server (1.19.4). Died on the main end island and came back within a minute- nothing there.  No one else online

Anddd, it happened to me today, twice. This is really the worst bug, I spent two hours farming in the nether for what ? Only to lose my whole stuff due to a bug. Please fix it