After encountering special mobs (with unique sounds) such as Evoker and Skeleton Horseman, their music keeps playing until the end of the mission even though you killed them.

Mode: Adventure

This issue happened in Creeper Woods and Pumpkin Pastures missions. I encountered Skeleton Horseman in Soggy Swamp, but didn't have this problem. 

Unfortunately I'm not able to reproduce it 100% and I'm not sure what's triggering the failure of the stop script.

What I expected to happen was...:

When I killed unique mobs their special music stopped.

What actually happened was...:

Instead, it continued playing until the end of mission. 

Steps to Reproduce:

1. Encounter one of the unique mobs (Evoker/Skeleton Horseman) in Creeper Woods or Pumpkin Pastures

2. Kill them

3. Their music should continue playing