spawn_entity behavior, witch isn't spawning a sheep

Build: 439604
Summary:
I modified this witch to spawn sheep. It doesn't.
Impact:
The witch doesn't spawn sheep. I have been able to make it successfully spawn items, but not other monsters or specifically, sheep. Works in 1.1.5.
Repro Steps:
1. Load this witch JSON
2. fight the witch or summon an iron_golem for it to fight.

Observed Results: It doesn't summon sheep
Expected Results: It should summon sheep. Will summon items no problem, but not sheep.
Screenshots/Videos attached: no

Notes: The JSON is valid and this behavior worked in 1.1.5. Without behavior pack documentation changes noted I see no reason that this shouldn't be working.