There is currently a known issue affecting the "non validated" user option causing users to be unable to reset their username and password.
Note: Is Validated---> This option verifies whether the password for the user to
log into application has been validated. If it is set to Yes, the user is able
to login. If it is set to No, the system will prompt the user to reset their
password upon the first login.
The workaround is to direct users to the "Forgot" password option (make sure email is properly set up in contact info).