Very bad FPS after creating wither

When creating a Wither and playing with 4 persons split screen, the performance becomes very bad, about 1 FPS while players are close to the wither. If leaving the area, FPS becomes normal again.

Tested on PS4 Pro.

Steps to reproduce:

1. Start a 4 player split screen session
2. Create a wither in overworld
3. FPS drops to very low, almost impossible to play the game.