My pets, horses, villages, cows, etc. all disappeared, even the ones with name tags

i went to the nether to go to the portal to the stronghold in my world to get books from the bookshelfs, and when i came back, all my dogs, cats, horses, llamas, villagers, etc. were gone, they disappeared, even the ones with a name tag. I hope when this bug gets fixed, it brings all of them back