If you send the request for password reset for a user in the restetPassword realm, you receive a mail with link to reset the password, if you click on it the password is reset and REST response contains the the realm with small letters. In 12.0.1 realm is displayed correctly with capital P.
Steps to reproduce:
1) Create realm resetPassword
2) Enable the forgot password service
3) Create user in realm resetPassword
4) Enable SMTP host (if needed)
5) Request password reset
REST response after clicking on link and resetting password:
Password is reset. REST response after password reset contains: "realm: resetPassword"
Password is reset. REST response after password reset contains: "realm: resetpassword"