Auth0, flask: Users need to login twice due to CSRF error

Question

When a user logs into my flask app it does not work first time, but it typically works on the second attempt. The following error occurs on the first login attempt:

MismatchingStateError: mismatching_state: CSRF Warning! State not equal in request and response

I did not have this problem when running on localhost on a windows PC. I obtained this problem when moving my code to a linode running ubuntu 20.04. I am considering flask in python3 as well as the following packages.

from flask import Flask
from flask import jsonify
from flask import redirect
from flask import render_template
from flask import session
from flask import url_for
from flask import request
from flask import send_from_directory
from authlib.integrations.flask_client import OAuth

My keys are fixed in a .env file. They are not randomly generated.

oauth = OAuth(app)

auth0 = oauth.register(
    'auth0',
    client_id=AUTH0_CLIENT_ID,
    client_secret=AUTH0_CLIENT_SECRET,
    api_base_url=AUTH0_BASE_URL,
    access_token_url=AUTH0_BASE_URL + '/oauth/token',
    authorize_url=AUTH0_BASE_URL + '/authorize',
    client_kwargs={
        'scope': 'openid profile email',
    },
)

The following code in the callback handling gives the CSRF error.

@app.route('/callback')
def callback_handling():
    auth0.authorize_access_token()
    resp = auth0.get('userinfo')