SQLite works, but PostgreSQL migrated database causes ERROR - Django 3.0

Situation

• I have built Django 3.0 project with a couple of applications.
• I have created the accounts app based on following course and it's github
• Than I have created an application fro authentication acc
• All this has been done in an SQLite database
• Previously I have tried out a PostgreSQL database for the early application that was working fine
• but now when I switch of in the settings.py file the SQLite to PostgreSQL I get an error i I try to log in
• If I switch back the settings.py to SQLite everything works perfectly (ex.: authentication, logging in with user, user doing things on the website with it's own settings)
• I use decorators.py to keep logged in users visiting the login and signup pages and that gives error when I switch to postgresql. I only use here HttpResponse that the error message contains

decorators.py

from django.http import HttpResponse
from django.shortcuts import redirect

def unauthenticated_user(view_func):
    def wrapper_func(request, *args, **kwargs):
        if request.user.is_authenticated:
            return redirect('home')
        else:
            return view_func(request, *args, **kwargs)

    return wrapper_func

def allowed_users(allowed_roles=[]):
    def decorator(view_func):
        def wrapper_func(request, *args, **kwargs):

            group = None
            if request.user.groups.exists():
                group = request.user.groups.all()[0].name

            if group in allowed_roles:
                return view_func(request, *args, **kwargs)
            else:
                return HttpResponse('Authorized')
        return wrapper_func
    return decorator

ERROR

If I log in while settings.py uses PostgreSQL. If I log out everything works out fine again. If I use SQL lite I can log in and everything works perfectly

ValueError at /
The view accounts.decorators.wrapper_function didn't return an HttpResponse object. It returned None instead.
Request Method: GET
Request URL:    http://localhost...
Django Version: 3.0
Exception Type: ValueError
Exception Value: The view accounts.decorators.wrapper_function didn't return an HttpResponse object. It returned None instead.
Exception Location: /Users/.../python3.7/site-packages/django/core/handlers/base.py in _get_response, line 126
Python Executable:  /Users/.../bin/python3
Python Version: 3.7.3
.....

Request information
USER MYUSERNAME
GET No GET data
POST No POST data
FILES  No FILES data
COOKIES ...
...

Tried to Solve

• The guide that I follow created user groups that I have done as well in my migrated postgreSQL database, but I have still received the same error as USER1 in the comment section.
  • This was the recommendation in the bottom section of the video
  • "USER1 i find it, i forgot to change the user's group!
  • --> USER2 go to admin panel and in you user section add customer in the chosen group section".
  • I have done exactly that and it did not worked the only difference is that I have used a migrated postgresql and they used the original SQLight that if I use than the whole thing works for me as well, but I want to make it work with PostgreSQL.
• I have data, tables in both database but PostgreSQL for some old staff and SQLite for everything.
  • I have tried to migrate the SQLite to PostgreSQL with this guide.
  • I have successfully created a copy of the SQLite database
  • but when I changed the settings to postgres and I try to python manage.py migrate it says Running migrations: No migrations to apply.
  • python manage.py loaddata db.json
  • The users are migrated (I can log in with them and get error just like with the only SQlite users, if I mistype the user or the password it does not lets me in) from SQLite but I don't see any of the data tables in Postgresql if I look it up with an IDE
• I have talked to other people on forums abut this many said that it is the decorator file that is problematic but It exactly occurs only at data base switching.
• I have created a new postgresql database and I have tried to migrate everything (the migration did not migrate everything already). Than I have tried to sign up with a new account an it gave me the following error message after filling out the form an pressing submit

DoesNotExist at /register/
Group matching query does not exist.