Custom tiles do not spawn equally per prefab

I've always wondered why some rooms in cave generate only a few resources and are surrounded by a large open space.Until I checked the file, and did the test.

(SpiderIncursion)

AddRoom("SpiderIncursion", {
    colour={r=.10,g=.08,b=.05,a=.50},
    value = WORLD_TILES.SINKHOLE,
    type = NODE_TYPE.Room,
    custom_tiles={
        GeneratorFunction = RUNCA.GeneratorFunction,
        data = {
            iterations=3,
            seed_mode=CA_SEED_MODE.SEED_CENTROID,
            num_random_points=1,
            translate={
                {tile = WORLD_TILES.SINKHOLE, items = {"grass"},                                      item_count=3},
                {tile = WORLD_TILES.SINKHOLE, items = {"sapling","berrybush"},                        item_count=5},
                {tile = WORLD_TILES.GRASS,    items = {"grass", "berrybush", "spiderden"},            item_count=10},
                {tile = WORLD_TILES.GRASS,    items = {"grass", "sapling", "evergreen", "spiderden"}, item_count=12},
                {tile = WORLD_TILES.GRASS,    items = {"evergreen", "sapling", "spiderden"},          item_count=10},
            },
            centroid= 	{tile=WORLD_TILES.FOREST, 	items={"cavelight"},			item_count=1},
        },
    },
    contents =  {
        distributepercent = .175,
        distributeprefabs =
        {
            cavelight = 25,
            cavelight_small = 25,
            cavelight_tiny = 25,

            spiderden = .1,
            rabbithouse = 1,

            fireflies = 1,
            sapling = 15,
            twiggytree = 6,
            evergreen = .25,
            berrybush = .5,
            berrybush_juicy = 0.25,
            blue_mushroom = .5,
            green_mushroom = .3,
            red_mushroom = .4,
            grass = .25,
            cave_fern = 20,
        },
    }
})

It seems to only generate the first one instead of generating all prefabs equally（except the fifth,just ignored）.I think that's why there's always only grass and saplings here.Something else is generated when I change the sort order.distributeprefabs is ignored and can't generate anything.

The same is true for the other two rooms.

（RabbitSinkhole）

AddRoom("RabbitSinkhole", {
    colour={r=.15,g=.18,b=.15,a=.50},
    value = WORLD_TILES.SINKHOLE,
    type = NODE_TYPE.Room,
    custom_tiles={
        GeneratorFunction = RUNCA.GeneratorFunction,
        data = {
            iterations=8,
            seed_mode=CA_SEED_MODE.SEED_CENTROID,
            num_random_points=1,
            translate={
                {tile = WORLD_TILES.GRASS, items = {"sapling","berrybush"},                          item_count = 5},
                {tile = WORLD_TILES.GRASS, items = {"grass", "berrybush", "rabbithouse"},            item_count = 10},
                {tile = WORLD_TILES.GRASS, items = {"grass", "sapling", "evergreen", "rabbithouse"}, item_count = 12},
                {tile = WORLD_TILES.GRASS, items = {"evergreen", "sapling", "rabbithouse"},          item_count = 10},
                {tile = WORLD_TILES.GRASS, items = {"not_used"},                                     item_count = 300},
            },
            centroid = {
                tile = WORLD_TILES.FOREST, items = {"cavelight"},                                    item_count = 1
            },
        },
    },
    contents =  {
        distributepercent = .175,
        distributeprefabs =
        {
            cavelight = 25,
            cavelight_small = 25,
            cavelight_tiny = 25,

            spiderden = .1,
            rabbithouse = 1,

            fireflies = 1,
            sapling = 15,
            twiggytree = 6,
            evergreen = .25,
            berrybush = .5,
            berrybush_juicy = 0.25,
            blue_mushroom = .5,
            green_mushroom = .3,
            red_mushroom = .4,
            grass = .25,
            cave_fern = 20,
        },
    }
})

（GreenMushNoise）

AddRoom("GreenMushNoise", {
    colour={r=.36,g=.32,b=.38,a=.50},
    value = WORLD_TILES.FUNGUSGREEN,
    tags = {"Hutch_Fishbowl"},
    custom_tiles={
        GeneratorFunction = RUNCA.GeneratorFunction,
        data = {iterations=8, seed_mode=CA_SEED_MODE.SEED_RANDOM, num_random_points=2,
            translate={
                {tile=WORLD_TILES.FUNGUSGREEN, items={"mushtree_small", "flower_cave", "cave_fern"}, item_count=20},
                {tile=WORLD_TILES.FUNGUSGREEN, items={"mushtree_small", "flower_cave", "cave_fern"}, item_count=20},
                {tile=WORLD_TILES.FUNGUSGREEN, items={"mushtree_small", "flower_cave", "cave_fern"}, item_count=20},
                {tile=WORLD_TILES.SINKHOLE, items={"evergreen", "grass", "sapling", "berrybush"}, item_count=20},
                {tile=WORLD_TILES.SINKHOLE, items={"evergreen", "grass", "sapling"}, item_count=20},
            },
        },
    },
    contents =  {
        distributepercent = .25,
        distributeprefabs=
        {
            mushtree_small = 2.0,
            green_mushroom = 2.0,
            flower_cave = 0.5,
            flower_cave_double = 0.2,
            flower_cave_triple = 0.2,

            cave_fern = 3.5,

            slurper = 0.001,
            rabbithouse = 0.005,
        },
    }
})