Entitys Disappearing And Despawning

I Have A Village With So Many Villagers And They Work All Over The Village And Do What They Need To Do. But In Real Life. When The Day Goes On. I Notice That I Am Starting To Loose Villagers And Wandering Traders. Also Villager Do Not Bread At All And I Never See Baby Villagers Also Other Entities Are Despawning Like Minecarts, Armor Stands, Tamed Mobs, Boats, And Other Entities.