Affects Version/s: Minecraft 1.14.3
Fix Version/s: None
Environment:Windows 10 Version 1809 Build 17763.557 Java Update 8 Version 211 (64-bit)
Put the summary of the bug you're having here
What I expected to happen was...:
No mobs spawning at any y-variable above light level 9.
What actually happened was...:
Mobs Spawn in at y=256 above light level 9.
Steps to Reproduce:
1. Build up to y=256 using only whole blocks such as dirt, glass, etc. and NOT slabs, carpet, etc.
2. Wait until both client light and server light are above 9.
3. Mobs spawn in.