You have created a customized copy of the user form: Main.UserForm.
Your form changes will only be visible in a user topic after it has been saved.
Please keep the UserRegistration form and the user form definition in sync. When you update the user form you need to edit/save the System.NewUserTemplate (not recommended, see below). This ensures that the fields are in the right order.
A form for new users
If a new user registers, the new user page is prefilled with the contents of System.NewUserTemplate. That template also contains a user form, based on the form definition in Main.UserForm.
You have created a custom user form, so you ought to use a custom 'new user' template as well. This will make your changes safe to future Foswiki upgrades.
To create your custom new user template, do this: