Affects Version/s: 1.14.30 Hotfix, 1.16.20
Fix Version/s: None
In the json behaviour pack the minimum is set to 9, but they require a minimum of 12.
Steps to reproduce :
1, make a mycelium platform high in the sky in a mooshroom island
2. place rows of torches
3. setup a few command blocks to replace the block where mooshroom spawn by an other block and kill the mooshroom when they spawn.
Mooshroom never spawn more than 2 blocks away from the torches.
I've attached a world download demonstrating that.
Mooshroom also have some spawn condition like the block where they spawn being mycelium, that is not in the json file. So I suppose there is some leftover code for mooshroom that raises the minimum light level specified in the json.