Been like this even in the 2 previous versions. Basically whenever the game freezes very badly that the game doesn't work until you either force close it by yourself or it the system does it by itself , a bunch of mobs(animals in fences) and villagers near me usually disappears for no reason. It also happens whenever the annoying auto save does it thing that opening your inventory or interacting with whatever decides to show that loading bar in front of your face and it won't go away unless your close the game. Likewise, playing with another player via locally(as in using 2 switch controllers via 1 game) lags so badly that when the game closes it also makes mobs and villagers disappear.  I tend to have my home filled with a bunch of animals I collected and started a functional village next to my home, together with my siblings' houses but it lags so badly.  So it's kinda disappointing that either the game itself or console couldn't handle this much entities and structures in 1 area...