Concurrency issue: Users are logged in as other users

[zzikkzzakk]

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

When multiple users accessed our webpage at once and (successfully logged in via this library). After a while some of them got logged in as other users in the backend. This was apparent as we show the username in the Frontend which we get from _id_token_claims['name'] . Also other requests e.g. for user history accessed data of the wrong user.
We tried to reproduce it in a controlled development environment with multiple users and simulated requests at once and checked if the MS user oid we set manually in the request matched the one acquired via _id_token_claims but couldn't reproduce the issue so far. This happened on release to a wider audience

Any log messages given by the failure

No errors seen

Expected/desired behavior

No concurrency issue

OS and Version?

Azure App Services, Python Stack

Versions

latest i.e. 0.16.6

Mention any other details that might be useful

Is this line

ms-identity-python-samples-common/ms_identity_web/django/middleware.py

Line 29 in 9b32cef

self.ms_identity_web.set_adapter(django_context_adapter)

which sets the adapter for the Middleware but the adapter is initialized with the current request, really thread safe, i.e. for multiple users at once?