[MC-186734] Zombified Piglin spawning on low y-levels

Zombified Piglin spawning is seriously decreased from the previous versions low in the world (y=8 and below approximately).

I tested using a custom json file that created a superflat empty nether dimension in the nether wastes.

Attachments

Please attach that .json file here so the issue can be reproduced easily.

I attached the .json file. Note that it also has an empty overworld, so enter spectator mode after opening the world before going to the nether.

Is this still an issue in 1.18-pre4?