hi sorry if im doing this wrong in anyway, first time reporting a bug.

well i was playing on a realm, almost all of our villagers just disappeared somehow, we thought they had just decided to drown in a fountain near by so we just decided to tear it down and start breeding the last two together to get our villagers back. while i was afk while waiting for potatoes to grow, about 10-30 blocks from the village, one of them just disappeared, i checked the area and there was no way for the villager to disappear or get killed in anyway. 
(i was standing where the lone 1x1 water is next to the farm, the house they where living in is incomplete but isnt a way to escape since theres a big gap between the house and the wall(look its small i just started it))

earlier there was a wandering trader near my house and while i wasnt looking, the llamas disappeared and left the leads behind and the trader was still alive. dont know if this is part of the bug but did seem a bit odd

the giant group of villagers disappearing and the llamas disappearing happened with someone else online.

this seems like a bug to me since ive never had this problem with villagers disappearing in my game.

thank you for reading.