Friendly mobs dissapear from my world

For context I spent a lot of time in a old village when this happened while I was building stuff on the village my villagers dissapeared I was on peaceful mode so zombies and pillagers couldn’t kill them but I didn’t have any beds or work stations before my villagers dissapeared they didn’t change their professions or lost them also I didn’t trade with them before the update. And the animals that are near my house which isn’t loaded while I am in the village all dissapeared they where all trapped on a fence I’m not sure if this a feature that I wasn’t aware of but include sure all those mobs aren’t coming back but if it is a feature please make people aware of it