the problem occures on a realm which i am not the admin of.
my villagers are in a closed system, so no zombies can enter. they live in an area over 3-4 chunks. im always online, mostly in my base. like 2-3 chunks away and sometimes they disappear, even with name tags. i try to keep them away from chunk borders, but im not sure if that is a myth.
its hard work to get them there and into the profession/trading i want. so it is very unfortunate that they just vanish.
thanks in advance
Environment
in an mountain, closed area. snow biome. high above deep dark, but in same chunk.
they only fix new snapshot bugs. they ignore 1.21.8 bugs now.