Baby polar bear model not correct

All baby polar bears' model pieces were disconnected from each other.

What I expected to happen was...:
Baby polar bear models are correct. When I reloaded the game, models were still not correct.

What actually happened was...:
Model pieces are not connected.

Steps to Reproduce:
1. Spawn baby polar bear; I've tried spawn eggs on adult polar bear, summoning then through commands, and them spawning naturally.