Account on + plugin do not work on

To reproduce:

  1. register an account in a plugin(firefox) as [email protected]
  2. Try to log into the site
  3. Try to reset password on site
    Neither login in nor password reset will work as the email will be considered invalid on the site.
    Additional comments:
    Confirmation email upon registration will be sent and work.
    I generated my password via password manager and saved it, so I know it is correct, but cannot log into the site.