Intermittent 'Failed to match request state with session state' with Django adaptor

[ciarancourtney]

This issue is for a: (mark with an x)

- [x] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Minimal steps to reproduce

Default Django setup as per Azure-Samples/ms-identity-python-django-tutorial

Any log messages given by the failure

Django error email report snippet:

•	/opt/master/venv/lib/python3.8/site-packages/ms_identity_web/__init__.py in _verify_state 
259.	
260.	            raise AuthSecurityError("Failed to match request state with session state")
261.	
Local Vars
Variable	Value
req_params	{'code': '0.AQ<redacted>AA',
 'session_state': 'aa8b2958-b1c4-4e71-a95c-a682c2180777',
 'state': 'c5af71b0-fc95-4d3c-896e-a5c8306d86f7'}
self	<ms_identity_web.IdentityWebPython object at 0x7fbda61c59a0>
session_state	None
state	'c5af71b0-fc95-4d3c-896e-a5c8306d86f7'

Expected/desired behavior

session_state should not be None and should match state param at https://github.com/Azure-Samples/ms-identity-python-samples-common/blob/main/ms_identity_web/__init__.py#L258

OS and Version?

Django 2.2 using gunicorn on Ubuntu 20.04 EC2

Versions

MSAL 1.12.0

Mention any other details that might be useful

Seems easier to repro using Firefox, but have seen using Edge/Chrome.

[hitanshsingla]

Hi, I'm on ms-identity-web (0.16.6), and when I login from two browser windows, then I get the same error.
Can anyone suggest a solution? Thank you!

Steps:

1. open login page in tab 1 (state is issued)
2. open login page in tab 2 (new state is issued)
3. completing login in tab 1 will result in "Failed to match…" error