Items and Mobs disappearing from reloading a game

Hi, playing on Android 1.17.40 Survival, extern saving, offline. I was in my base and close via menu button save & exit. On the other day I load and sense all my villagers, minecarts, cows are gone. An empty castle. What can I do? I have more than 200 Hours and now these are disappearing? How to play when all things are able to get away?