I would suggest using
rest_framework.test.APITransactionTestCase instead of
This seems to be a code issue, are you using django-cors-headers and new open-api based solution? core API is kind of deprecated now.
The 500 Internal Server Error is a "server-side" error, meaning the problem is not with your PC or Internet connection but instead is a problem with the web site’s server. … So definitely the problem is in servers you were using.