Is there a height limit for Husks to spawn in (java minecraft)

Question

I was in a desert biome and husks were spawning, I then decided to build a spawn fall trap in the sky (level 88) but even though its dark inside the spawn area, and 3 blocks high i am not getting husks). I build the trap above thr same area where they had previously spawned.

Im only getting Skellis, Zombies, Creepers, Spiders, Witches, Endermen (basically everything BUT the Husks).

Im playing on a Skyblock 3.07 world on Minecraft Java on PC version 1.12.2 Locally on my pc. The reason i want the Husks is in that Skyblock version they drop Sand, the Zombies drop Gravel.

Its got me stumped, im thinking it must be a height thing, but cant seem to find any data on if any limmitations.

Answer 1

Seems no answer in nearly two years so I will necropost in case anybody else is searching.

Husks only spawn if the block they would spawn on can see the sky.  If your setup is dark because it has a ceiling then that is why you have no husks.