Summary:
When the game is in Peaceful, hostile mobs are spawning in for a split second before flashing red, dying, and disappearing. You can hear their death sound too. Appears to only affect the End and Nether.

Steps to Reproduce:

1. Set the game difficulty to Peaceful
2. Travel to the End

Observed Results:
Endermen can be seen spawning in for a split second.

Expected Results:
Hostile mobs should not be spawning at all.

Screenshots/Videos attached: Yes

Notes: