This just happened after the 1.19.40 release...

Seed: -1035687192
Coordinates: (-720, ?, 205)

The Ancient City in question is directly below the world spawn.

I had a gold farm (Flickering nether portal that drops zombified piglins into a trident killer) above y-0 and it worked as it should.

After 1.19.40, it no longer spawned zombified piglins. It's directly above an Ancient City. Apparently, the fix to stop hostile mobs from spawning in an Ancient City stops mobs from spawning from the bottom of the world to at least the surface.

I'm thinking it's all cave spawns that are being prevented by the Ancient City. I am noticing some foxes spawning on the surface.