Box of horror mobs not spawning

[WasabiPickles]

Describe the Bug

I've been playing FNF for about a week now on a server hosted by BisectHosting and have yet to see any of the box of horror mobs spawning. I have the structures but not the mobs. I've tried spawning them in creative but can't do that because of another mod in the modpack, so I can't tell if its my server or modpack. Is the spawn rate just insanely low? If so how do I increase it. Most of the mobs that are spawning are vanilla with a few being modded.

Reproduction Steps

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Screenshots and Videos

No response

Crash Report or Log

No response

Operating System

Windows 11

Minecraft Version

1.20.1

Modloader

Forge

Modpack Version

v1.0.8

Other Mods

No response