More of a bug, but noplace to put it but here.
If a coop had say 100 apples and 20 chickens in it and that group quits, they animals die of too much poo.
If a new group moves in and puts animals in those coops they will die the next tick of too much poo.
Coops left alone will kill the animals, say the poo is 200%. The poo level will then slowly decrease over time back to zero - but the coop acts like it still has 200% poo the first tick new animals are placed in it. Basically it's invisible poo that the game thinks is still there, but does not show and can't be cleaned.
Right now I just destroy and remake the coops for players about twice a week, and suggest to new players that they do not use old coops they find.
Again, GMs on private servers will happily tell you what they are consistently having to go fix so you can tweak them before MMO release. But nobody to tell and there isn't even a bug report area in the forums.