Sky becomes normal when unloading Wither and reloading the world

Xperia Z5

When you spawn a wither. The sky becomes darker. But when you reload the world while the wither is there. It goes back to its normal look

Steps to reproduce

• Start a creative world.
• Create a Wither.
• Notice that the sky changes to wither sky.
• Leave the area where the wither is until the wither heath bar is no longer shown on your screen.
• Reopen the world.
• Notice that the sky is normal again.
• Go back to where the wither is.
• Notice that the sky changes back to wither sky.