Django Database Routing

I am having 3 databases defined in the Settings.py and routers for two apps in the respective app folders. When I try to run manage.py migrate --database="app_db" respectively for apps, it only runs default and second database list item. If I change the order of database list it won't perform the last one but only second one.

Settings.py

INSTALLED_APPS = [
    # django apps
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    # my apps
    "cred",
    "dms",
    # third party apps
    "rest_framework",
]


DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.sqlite3",
        "NAME": BASE_DIR / "databases/db.sqlite3",
    },
    "dms_db": {
        "ENGINE": "django.db.backends.sqlite3",
        "NAME": BASE_DIR / "databases/dms.sqlite3",
    },
    "cred_db": {
        "ENGINE": "django.db.backends.sqlite3",
        "NAME": BASE_DIR / "databases/cred.sqlite3",
    },
}

DATABASE_ROUTERS = [
    "dms.routers.DMSRouter",
    "cred.routers.CredRouter",
]

AUTH_USER_MODEL = "cred.User"
CRED_DB_ROUTER = "cred_db"
DMS_DB_ROUTER = "dms_db"

if I put dms_db at list index 1 then it will migrate but cred_db won't. If I put cred_db at index 1 then it will migrate but dms_db won't.

Cred.Router.py

from django.conf import settings


class CredRouter:
    route_app_labels = ["auth", "cred", "contenttypes"]

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return settings.CRED_DB_ROUTER
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return settings.CRED_DB_ROUTER
        return None

    def allow_relation(self, obj1, obj2, **hints):
        if (
            obj1._meta.app_label in self.route_app_labels
            or obj2._meta.app_label in self.route_app_labels
        ):
            return True
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.route_app_labels:
            return db == settings.CRED_DB_ROUTER
        return False

dms.router.py

from django.conf import settings


class DMSRouter:
    route_app_labels = [
        "dms",
    ]

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:  # noqa
            return settings.DMS_DB_ROUTER
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:  # noqa
            return settings.DMS_DB_ROUTER
        return None

    def allow_relation(self, obj1, obj2, **hints):
        if (
            obj1._meta.app_label in self.route_app_labels  # noqa
            or obj2._meta.app_label in self.route_app_labels  # noqa
        ):
            return True
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.route_app_labels:
            return db == settings.DMS_DB_ROUTER
        return False

What I am running

Only initial_0001.py is there in migrations folder. So I guess? it is not making some issue. Not sure tho.

manage.py makemigrations 
manage.py migrate
manage.py migrate --database="cred_db"
manage.py migrate --database="dms_db"

All the models share this structure exactly.

class Organization(models.Model):
    name = models.CharField(max_length=255)
    email = models.EmailField()
    codename = models.CharField(max_length=254, unique=True)
    ... 

    objects = models.Manager()

    class Meta:
        verbose_name = _("organization")
        verbose_name_plural = _("organization")

As the project evolves we will be having more databases connections as we will be integrating our existing Django apps and each has a dedicated databases server already established. So this project will be connecting to at min 8-10 different databases. Manually migrating each by moving will be a issue for so many of them.