Put the summary of the bug you're having here

What I expected to happen was...:
When I log in to my realm, my mobs (horses, llamas, cats, dogs, villagers, et. al.) that I have captured, tamed, etc. will still be there.

What actually happened was...:
My mobs and villagers are actually gone/despawned/disappeared.

Steps to Reproduce:
1. Log in to realm
2. Do things with mobs (tame, name, put in pen, lead/leash to fence, trade with villagers, etc)
3. Play
4. Leave realm
5. Mobs are despawned when you log back in