Koi fish do not prevent zombie sieges from spawning near villages at night

[ScaryPoltergeist]

Minecraft version

1.20.1

Mod version

4.1.2

NeoForge version

Forge 47.4.10

Description

Disabling "Block only natural spawns" had no effect.
The zombies seem to be spawning as part of a zombie siege, an event which occurs around villages at night.

Steps to reproduce

I placed a koi fish in a one block hole in the ground covered by a trap door, surrounded by a 65x65 fence designating the koi's area of effect. Next to the koi, I surrounded a villager with oak planks and a job site block, which seems to constitute a village for the purpose of zombie sieges.

After setting the time to midnight, a large number of zombies will continuously spawn and walk towards the villager.

Mod list

Mod List:
client-1.20.1-20230612.114412-srg.jar |Minecraft |minecraft |1.20.1 |DONE |Manifest: a1:d4:5e:04:4f:d3:d6:e0:7b:37:97:cf:77:b0:de:ad:4a:47:ce:8c:96:49:5f:0a:cf:8c:ae:b2:6d:4b:8a:3f
blueprint-1.20.1-7.1.4.jar |Blueprint |blueprint |7.1.3 |DONE |Manifest: NOSIGNATURE
mixinextras-forge-0.4.1.jar |MixinExtras |mixinextras |0.4.1 |DONE |Manifest: NOSIGNATURE
environmental-1.20.1-4.1.2.jar |Environmental |environmental |4.1.2 |DONE |Manifest: NOSIGNATURE
forge-1.20.1-47.4.10-universal.jar |Forge |forge |47.4.10 |DONE |Manifest: 84:ce:76:e8:45:35:e4:0e:63:86:df:47:59:80:0f:67:6c:c1:5f:6e:5f:4d:b3:54:47:1a:9f:7f:ed:5e:f2:90

Logs

https://pastebin.com/0ZVUVQVj

Confirmation

• I have tested this on a minimal instance

Confirmation

• I have verified that this is not a duplicate of an existing (open or closed) issue

Confirmation

• I have verified this issue is present without rendering & shader mods like Optifine, Iris, Oculus, etc.

[ScaryPoltergeist]

After learning that koi fish do not prevent spawns in a square but in a circle, I built a diamond shaped fence around the village instead to remove gaps where the koi effect was not present. Issue still occurs.