exactly what the title says. this is on windows 10 arm btw

when you move out of villager tick radius(vtr), the game attempts to save the villagers. theres a chance the save operation will fail and the villagers will disappear.

the vtr is about 70 meters. from my experience, rapidly moving in and out of range will result in failed saves to chunk.

on an anecdotal note, when you leave your base to go collect some sand and upon returning find four max level librarians and your cleric have disappeared from your iron farm; you notice.

i understand that the mods on this site dont actually play the game. they re busy moderating the site. fine. but then dont discount and pass over the data provided by people who are actualy playing the game.

this bug wasnt discovered in creative mode.

it occurs in real survival games in areas with high tick lag do to all the villagers, redstone machines, mob farms and etcetera that simultaneously operate in a players base in a real game.

so if your going to try to reproduce it, try playing the game... and if you cant do that, at least try and simulate the tick lag real players experience. throw in a couple dozen repeater clocks...

heres a link to the iron farm i use. it suffers zero villager loss outside of failed saves.

https://www.minecraftforum.net/forums/minecraft/discussion/3031732-how-to-build-an-iron-farm