Django doesn't start signal. Or is that how it should be?

Question

PostgreSQL

Good day.
I have two Django projects ( VetpharmCommerce and VetDirectory ) on different databases, but they share a common table Users. Done like this:

DATABASES = {
  'default': {
    'ENGINE': 'django.db.backends.postgresql_psycopg2',
    'NAME': 'vet-directory',
    'USER': 'vetpharm',
    'PASSWORD': '',
    'HOST': '127.0.0.1',
    'PORT': '',
    'TEST': {
      'ENGINE': 'django.db.backends.sqlite3',
    }
  },
  'users': {
    'ENGINE': "django.db.backends.postgresql_psycopg2",
    'NAME': "vetpharm_commerce",
    'USER': "vetpharm",
    'PASSWORD': "",
    'HOST': "127.0.0.1",
    'PORT': "5432"
  }
}

VetpharmCommerce has a logic for creating a profile Userwith a signal:

def create_profile(sender, instance, created, **kwargs):
    """ Creates profile for user """
    CustomerProfile.objects.get_or_create(user=instance)

post_save.connect(create_profile, sender=compat.AUTH_USER_MODEL)

When I register Userwith VetpharmCommerce , then everything is OK, CustomerProfileit is created, but if I Userregister with VetDirectory , then the record Useris created, but CustomerProfilenot.
Here's my question: how to make it so that it would be CustomerProfilecreated regardless of which site you registered on? Can I get by with one signal on VetpharmCommerce , or does VetDirectory also need the same signal?
I will be very grateful for your help.
PS Sorry for the bad Russian.