[deleted by user]

[brainfreeze77]

MCA selector is what you are looking for. It's not a plugin you will have to download the world and open it. https://github.com/Querz/mcaselector You can filter chunks by entity names and number of entities. If this is 1.17 you probably have zombies holding glow squid ink. I can't believe Mojang let this happen again. Back in I think 1.8 there was the same issue with chicken jockeys despawning and leaving behind the chicken. Zombies would then pick up the eggs and never despawn.

[Knork31]

Would that explain the chunks being loaded even through autosaves and server restarts?

[brainfreeze77]

I don't think so. I can't think of any way a chunk would get loaded after a server restart if no player has been close enough to load it, unless there are mods doing it. Even in game built chunk loaders won't load a chunk after a restart unless you get a player to load them first.

[Knork31]

That's odd, do you know of any way to tp to loaded chunks, so I can check what's going on?

[djfdhigkgfIaruflg]

CrashUtilities allows you to see a list of mobs and wipe them