dotenv celery docker container not updating immediately after change in .env file

Question

I'm using dotenv within a docker celery container.
The container has the code below.

In between runs I change the content of .env1 from LOGGING_CONF_FILE=logging1.yaml to LOGGING_CONF_FILE=logging2.yaml

I then touch the file __init__.py which trigerrs a reload of the app

I expect to see in the console: LOGGING_CONF_FILE10 logging2.yaml but I still see LOGGING_CONF_FILE10 logging1.yaml

If I touch the file __init__.py again, which triggers another reload of the app, I do see in the console: LOGGING_CONF_FILE10 logging2.yaml as expected.

1. Why dotenv isn't picking up the changes in the .env1 file immediately?
   
2. Also, why does "os.unsetenv" and "os.putenv" not unsetting the variable? When I print the value of LOGGING_CONF_FILE, I'm getting some value (and not undefined on empty string).
   

Thanks

cat .env1
...
LOGGING_CONF_FILE=logging1.yaml

def create_app(config_class=Config):
    print( 'BEG create_app' )

    app = Flask(__name__)
    # app.app_context().push()

    app.config.from_object(config_class)

    from app.errors import bp as errors_bp
    app.register_blueprint(errors_bp)

    db.init_app(app)
    mail.init_app(app)
    bootstrap.init_app(app)
    pagedown.init_app(app)
    migrate.init_app(app, db)
    # auth = HTTPBasicAuth()
    # auth_token = HTTPBasicAuth()
    login.init_app(app)

    class ContextTask(celery.Task):
        def __call__(self, *args, **kwargs):
            with app.app_context():
                return self.run(*args, **kwargs)

    celery.conf.update(app.config)
    celery.Task = ContextTask
...

Answer 1

The problem was that I had load_dotenv called in 2 places.
In the first/second call it was called without/with the option "override=True".
The two load_dotenv calls were competing where the first one honored existing os variables, and the otherone overrided them.
This led to unpredictable values for the environment variables.