Django: Makemigration Error "models.E028" and "models.E340" after extending Authuser (legacy MySQL)

Question

I connected my Django project to a legacy MySQL DB and did a first migration.

I then extended the AuthUser model with a "NewUser" model (made sure that AUTH_USER_MODEL settings.py to reference 'appname.NewUser')

When running makemigrations I get these error messages:

models.E028

account_emailaddress: (models.E028) db_table 'account_emailaddress' is used by multiple models: seasonscan_api.AccountEmailaddress, account.EmailAddress.
account_emailconfirmation: (models.E028) ...(same error)
auth_group: (models.E028) ...(same error)
auth_permission: (models.E028) ...(same error)
django_admin_log: (models.E028) ...(same error)
django_content_type: (models.E028) ...(same error)
django_session: (models.E028) ...(same error)
django_site: (models.E028) ...(same error)
socialaccount_socialaccount: (models.E028) ...(same error)
socialaccount_socialapp: (models.E028) ...(same error)
socialaccount_socialtoken: (models.E028) ...(same error)

fields.E340

auth.Group.permissions: (fields.E340) The field's intermediary table 'auth_group_permissions' clashes with the table name of 'seasonscan_api.AuthGroupPermissions'.
socialaccount.SocialApp.sites: (fields.E340) ...(same error)

I checked the docs which didnt show more than the error message without additional info. Any advice would help me a lot.

Here the models as reference:

from django.db import models
from django.utils.translation import gettext_lazy as _
from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin, BaseUserManager
from django.db.models.signals import post_save

class AuthGroup(models.Model):
    name = models.CharField(unique=True, max_length=150)

    class Meta:
        managed = True
        db_table = 'auth_group'


class AuthGroupPermissions(models.Model):
    id = models.BigAutoField(primary_key=True)
    group = models.ForeignKey('AuthGroup', on_delete=models.CASCADE, related_name='authgroup_authgrouppermissions')
    permission = models.ForeignKey('AuthPermission', on_delete=models.CASCADE, related_name='authpermission_authgrouppermissions')

    class Meta:
        managed = True
        db_table = 'auth_group_permissions'
        unique_together = (('group', 'permission'),)


class AuthPermission(models.Model):
    name = models.CharField(max_length=255)
    content_type = models.ForeignKey('DjangoContentType', on_delete=models.CASCADE, related_name='djangocontenttype_authpermissions')
    codename = models.CharField(max_length=100)

    class Meta:
        managed = True
        db_table = 'auth_permission'
        unique_together = (('content_type', 'codename'),)


class AuthUserGroups(models.Model):
    id = models.BigAutoField(primary_key=True)
    user = models.ForeignKey('NewUser', on_delete=models.CASCADE, related_name='newuser_authusergroups')
    group = models.ForeignKey('AuthGroup', on_delete=models.CASCADE, related_name='authgroup_authusergroups')

    class Meta:
        managed = True
        db_table = 'auth_user_groups'
        unique_together = (('user', 'group'),)


class AuthUserUserPermissions(models.Model):
    id = models.BigAutoField(primary_key=True)
    user = models.ForeignKey('NewUser', on_delete=models.CASCADE, related_name='newuser_authuseruserpermissions')
    permission = models.ForeignKey('AuthPermission', on_delete=models.CASCADE, related_name='authpermission_authuseruserpermissions')

    class Meta:
        managed = True
        db_table = 'auth_user_user_permissions'
        unique_together = (('user', 'permission'),)


class DjangoAdminLog(models.Model):
    action_time = models.DateTimeField()
    object_id = models.TextField(blank=True, null=True)
    object_repr = models.CharField(max_length=200)
    action_flag = models.PositiveSmallIntegerField()
    change_message = models.TextField()
    content_type = models.ForeignKey('DjangoContentType', on_delete=models.CASCADE, blank=True, null=True, related_name='djangocontenttype_djangoadminlog')
    user = models.ForeignKey('NewUser', on_delete=models.CASCADE, related_name='newuser_djangoadminlog')

    class Meta:
        managed = True
        db_table = 'django_admin_log'


class DjangoContentType(models.Model):
    app_label = models.CharField(max_length=100)
    model = models.CharField(max_length=100)

    class Meta:
        managed = True
        db_table = 'django_content_type'
        unique_together = (('app_label', 'model'),)


class DjangoMigrations(models.Model):
    id = models.BigAutoField(primary_key=True)
    app = models.CharField(max_length=255)
    name = models.CharField(max_length=255)
    applied = models.DateTimeField()

    class Meta:
        managed = True
        db_table = 'django_migrations'


class DjangoSession(models.Model):
    session_key = models.CharField(primary_key=True, max_length=40)
    session_data = models.TextField()
    expire_date = models.DateTimeField()

    class Meta:
        managed = True
        db_table = 'django_session'


class AccountEmailaddress(models.Model):
    email = models.CharField(unique=True, max_length=254)
    verified = models.IntegerField()
    primary = models.IntegerField()
    user = models.ForeignKey('NewUser', on_delete=models.CASCADE)

    class Meta:
        managed = True
        db_table = 'account_emailaddress'


class AccountEmailconfirmation(models.Model):
    created = models.DateTimeField()
    sent = models.DateTimeField(blank=True, null=True)
    key = models.CharField(unique=True, max_length=64)
    email_address = models.ForeignKey(AccountEmailaddress, on_delete=models.CASCADE)

    class Meta:
        managed = True
        db_table = 'account_emailconfirmation'


class DjangoSite(models.Model):
    domain = models.CharField(unique=True, max_length=100)
    name = models.CharField(max_length=50)

    class Meta:
        managed = True
        db_table = 'django_site'


class SocialaccountSocialaccount(models.Model):
    provider = models.CharField(max_length=30)
    uid = models.CharField(max_length=191)
    last_login = models.DateTimeField()
    date_joined = models.DateTimeField()
    extra_data = models.TextField()
    user = models.ForeignKey('NewUser', on_delete=models.CASCADE)

    class Meta:
        managed = True
        db_table = 'socialaccount_socialaccount'
        unique_together = (('provider', 'uid'),)


class SocialaccountSocialapp(models.Model):
    provider = models.CharField(max_length=30)
    name = models.CharField(max_length=40)
    client_id = models.CharField(max_length=191)
    secret = models.CharField(max_length=191)
    key = models.CharField(max_length=191)

    class Meta:
        managed = True
        db_table = 'socialaccount_socialapp'


class SocialaccountSocialappSites(models.Model):
    id = models.BigAutoField(primary_key=True)
    socialapp = models.ForeignKey(SocialaccountSocialapp, on_delete=models.CASCADE)
    site = models.ForeignKey(DjangoSite, on_delete=models.CASCADE)

    class Meta:
        managed = True
        db_table = 'socialaccount_socialapp_sites'
        unique_together = (('socialapp', 'site'),)


class SocialaccountSocialtoken(models.Model):
    token = models.TextField()
    token_secret = models.TextField()
    expires_at = models.DateTimeField(blank=True, null=True)
    account = models.ForeignKey(SocialaccountSocialaccount, on_delete=models.CASCADE)
    app = models.ForeignKey(SocialaccountSocialapp, on_delete=models.CASCADE)

    class Meta:
        managed = True
        db_table = 'socialaccount_socialtoken'
        unique_together = (('app', 'account'),)

###
### user and membership, subcription and payment related

class CustomAccountManager(BaseUserManager):

    def create_superuser(self, email, user_name, first_name, last_name, password, **other_fields):

        other_fields.setdefault('is_staff', True)
        other_fields.setdefault('is_superuser', True)
        other_fields.setdefault('is_active', True)

        if other_fields.get('is_staff') is not True:
            raise ValueError('Superuser must be assigned to is_staff=True.')

        if other_fields.get('is_superuser') is not True:
            raise ValueError('Superuser must be assigned to is_superuser=True.')

        return self.create_user(email, user_name, first_name, last_name, password, **other_fields)

    def create_user(self, email, user_name, first_name, last_name, password, **other_fields):

        if not email:
            raise ValueError(_("You must provide an email address"))
        if not user_name:
            raise ValueError(_("You must provide a user name"))
        if not password:
            raise ValueError(_("You must provide a password"))

        email = self.normalize_email(email)
        user = self.model(email=email, user_name=user_name, first_name=first_name, last_name=last_name, **other_fields)
        user.set_password(password)
        user.save()

        return user


class NewUser(AbstractBaseUser):
    password = models.CharField(_('password'),max_length=128)
    last_login = models.DateTimeField(blank=True, null=True)
    username = models.CharField(_('username'), unique=True, max_length=150)
    first_name = models.CharField(_('first name'), max_length=150)
    last_name = models.CharField(_('last name'), max_length=150)
    email = models.EmailField(_('email address'), unique=True)
    is_superuser = models.BooleanField(default=False)
    is_staff = models.BooleanField(default=False)
    is_contributor = models.BooleanField(default=False)
    is_extension_user = models.BooleanField(default=False)
    is_developer_user = models.BooleanField(default=False)
    is_newsletter_member = models.BooleanField(default=True)
    is_active = models.BooleanField(default=False)
    date_joined = models.DateTimeField(auto_now_add=True)

    objects = CustomAccountManager()

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['user_name', 'first_name', 'last_name']

    class Meta:
        managed = True
        db_table = 'new_user'

    def __str__(self):
        return self.user_name

app-specific models continuing below...

Thank you!