The assertRedirects method of TestCase doesn't work correctly with https redirects. There are actually two problems here.
Take the following scenario. You access a view with test client mimicking https by passing in **{'wsgi.url_scheme':'https'}. This view then redirects to a relative url which is converted by fix_location_header to an absolute url with https since the request is_secure(). So far so good.
But assertRedirects will blatantly ignore the scheme, checking the redirect url without the scheme. Since I have views that will redirect to https if not called with https, this will fail because the redirect check will again be redirected because the scheme was ignored.
This first problem can be fixed by adding **{'wsgi.url_scheme':scheme} to the redirect check and also taking the scheme into account when matching the url with expected, but this creates another problem. The fix_location_header response fix will build the absolute url using request.get_host(), which for the test client will return testserver:80. The port part is not expected by assertRedirects, which again fails, trying to match the expected https://testserver/some/path with https://testserver:80/some/path.
Change UI/UX from NULL to False.