Foxes which trust a player will attack chickens and rabbits when the player leaves and rejoins the world.
Steps to Reproduce:
- Spawn two foxes
- Breed them
- Run this command:
/data modify entity @n[type=fox] Age set value 0
- Spawn chickens/rabbits around the fox
→The fox will not attack the chickens/rabbits
- Leave and rejoin the world
→The fox now attacks the chickens/rabbits