[1.16] Steve spawns in the custom biome if though it isn't set as valid spawn

The title is very explanatory, I'd like to know if I'm mistaken about the isValidSpawnBiomeForPlayer(), or if there's something wrong with the code:

@Mod.EventBusSubscriber(modid = TutorialMod.MOD_ID, bus = Mod.EventBusSubscriber.Bus.MOD)
public class ModBiomes {

    public static final DeferredRegister<Biome> BIOMES = DeferredRegister.create(ForgeRegistries.BIOMES, TutorialMod.MOD_ID);

    public static final RegistryObject<Biome> TEST_BIOME = BIOMES.register("test_biome", () -> Maker.TestBiome());

    @SubscribeEvent
    public static void setupBiomes(FMLCommonSetupEvent event) {
        event.enqueueWork(() ->
            setupBiome(TEST_BIOME.get(), BiomeManager.BiomeType.WARM, 1500,
                Type.FOREST, Type.COLD, Type.OVERWORLD, Type.WET)
        );
    }

    private static void setupBiome(Biome biome, BiomeManager.BiomeType biomeType, int weight, BiomeDictionary.Type... types) {
        RegistryKey<Biome> key = RegistryKey.getOrCreateKey(
            ForgeRegistries.Keys.BIOMES,
            Objects.requireNonNull(ForgeRegistries.BIOMES.getKey(biome), "Biome registry name was null"));

        BiomeDictionary.addTypes(key, types);
        BiomeManager.addBiome(biomeType, new BiomeManager.BiomeEntry(key, weight));
    }

    private static class Maker {

        private static MobSpawnInfo.Builder getStandardMobSpawnBuilder() {
            MobSpawnInfo.Builder mobspawninfo$builder = new MobSpawnInfo.Builder();
            DefaultBiomeFeatures.withPassiveMobs(mobspawninfo$builder);
            DefaultBiomeFeatures.withBatsAndHostiles(mobspawninfo$builder);
            return mobspawninfo$builder;
        }

        private static Biome TestBiome() {
            BiomeGenerationSettings genset = new BiomeGenerationSettings.Builder()
                .withCarver(GenerationStage.Carving.AIR, ConfiguredCarvers.field_243767_a)
                .withCarver(GenerationStage.Carving.AIR, ConfiguredCarvers.field_243768_b)
                .withFeature(GenerationStage.Decoration.VEGETAL_DECORATION, Features.FANCY_OAK)
                .withFeature(GenerationStage.Decoration.UNDERGROUND_ORES, Features.ORE_COAL)
                .withFeature(GenerationStage.Decoration.UNDERGROUND_ORES, Features.ORE_GOLD)
                .withFeature(GenerationStage.Decoration.UNDERGROUND_ORES, Features.ORE_IRON)
                .withFeature(GenerationStage.Decoration.UNDERGROUND_ORES, Features.ORE_DIAMOND)
                .withStructure(StructureFeatures.END_CITY)
                .withSurfaceBuilder(ConfiguredSurfaceBuilders.field_244178_j)
                .build();

            MobSpawnInfo mobSpawn = getStandardMobSpawnBuilder().copy();

            BiomeAmbience ambience = new BiomeAmbience.Builder()
                .withGrassColor(0xDA67C1)
                .setFogColor(0xEEEEEE)
                .setWaterColor(0xCF21B8)
                .setWaterFogColor(0xCF78C5)
                .withSkyColor(0xE83452)
                .withFoliageColor(0xCA57C1)
                .build();

            return new Biome.Builder()
                .category(Biome.Category.FOREST)
                .withTemperatureModifier(Biome.TemperatureModifier.NONE)
                .withGenerationSettings(genset)
                .withMobSpawnSettings(mobSpawn)
                .depth(0.123f)
                .scale(0.4f)
                .downfall(.4f)
                .precipitation(Biome.RainType.SNOW)
                .temperature(.8f)
                .setEffects(ambience)
                .build();
        }
    }
}

Edited December 4, 20204 yr by kiou.23