waitress-serve giving ModuleNotFoundError

Question

I have a Flask app (python 3.7) that runs perfectly fine using Flask run command, its build using the factory pattern. However, I would like to run it with a production optimized wsgi server, running on windows/linux.

However, when I try to run this using waitress:

waitress-serve --host 127.0.0.1 --call 'ws:create_app'

I end up with the following error:

There was an exception (ModuleNotFoundError) importing your module.

It had these arguments:
1. No module named 'ws.models'

the project structure looks as follows:

|_ws
  |_ __init__.py
  |_ commands.py
  |_ config.py
  |_ helper_schemas.py
  |_ router.py
  |_ models
    |_ __init__.py
    |_ user.py
    |_ event.py
    |_ analytics.py
    |_ whisky.py
  |_ api
     |_ __init__.py
     |_V1
       |_ __init__.py
       |_ user.py
       |_ event.py

my main ws -> __init__.py file looks like this:

import sentry_sdk
from flask import Flask, session
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
from flask_restful import Api
from flask_cors import CORS

from .config import *
from flask_migrate import Migrate

db = SQLAlchemy()
ma = Marshmallow()
api = Api()

def create_app():
    app = Flask('__name__')
    CORS(
        app,
        origins=['http://localhost:8100', 'http://localhost:8101', ],
        supports_credentials=True
    )

    # env_config = os.getenv("APP_SETTINGS", "config.DevelopmentConfig")
    configuration = Config
    if app.debug:

        configuration = DevelopmentConfig
    else:
        print("[APP] Running production!")
        configuration = ProductionConfig
    app.config.from_object(configuration)
    db.init_app(app)
    ma.init_app(app)
    from . import router
    app.register_blueprint(router.bp)
    with app.app_context():
        from .api import V1
        app.register_blueprint(V1.api_bp)
        from . import commands
        app.cli.add_command(commands.tools_cli)
    app.secret_key = configuration.SECRET_KEY
    SESSION_TYPE = configuration.SESSION_TYPE
    Migrate(app, db)
    @app.before_request
    def before_request():
        session.permanent = True
    return app


from .models.user import *
from .models.analytics import *
from .models.event import *
from .models.whisky import *

each of the files under models does a from ws import db and for the ones under api its from ws import ma, db

I have tried a LOT of things and searched everywhere but I cannot seem to get rid of the error. Any ideas?