Iron Golems spawn in the ground

Iron Golems spawn in the ground

What I expected to happen was Iron Golems to spawn and walk around the village to protect villagers:

What actually happened was...:
The Iron golems spawn one block in the ground and dont move or attack non-friendly entities.

Steps to Reproduce:
1. Add buildings and doors to a village
2. Encourage villagers to start breeding
3. Iron Golems spawn as village populates