LoginView Error when going back to login page

[Jodel Asur]

I'm having an issue with LoginView when we go back to the login page using the browser back button. I've deployed a simple web app (https://jodelasur.pythonanywhere.com) so you can test for yourself.

Steps to recreate:

1. Enter invalid (random) credentials and submit. You should see the "Your username didn't match" error.
2. Enter valid credentials (user: user, password: userpassworduser). You should be logged-in successfully and redirected to home page.
3. Press the back button.

Actual output: Browser error (Chrome: Confirm Form Resubmission, Firefox: Document Expired).

Expected output: Still redirect to home page, since l'm already authenticated.

If I don't enter invalid credentials as the first step (i.e. just do steps 2 and 3), no error page appears, and I get the expected output of being redirected to the home page even after pressing the back button.

Here's the repo url if you need to see the code: https://github.com/jodelasur/login_view_test.

How do I avoid this error?