To reproduce the issue:

  1. Open the DevTools window to see logs in the browser console
  2. Enter a random email and password
  3. Submit
  4. Click "Save" on the Firefox popup asking whether you want to save the entered credentials
  5. Reload the page
  6. Firefox should autofill both the email and password fields
  7. Pressing Submit again will log an empty email (wrong, change event not dispatched) and the autofilled password (correct, change event dispatched)