I'm using a map that I have converted from the Minecraft Xbox Edition. However this issue seems to exist with all the new worlds I have created as well. I created a trade hall with about 30 villagers and iron golems started to spawn. After accidently hitting a villager, the iron golems become hostile like normal, but remain hostile even after death (both by the hostile iron golem or other mobs) and respawn. They remain hostile even after switching difficulty to peaceful and back to any of the other difficulties, they also remain hostile when switching between creative and survival mode. This is true for all new iron golems that spawn in or around this trade hall.