In visual mode you can specify that the nickname should be auto-generated, so that it is not included as a form field to be completed.
We have a current issue with the expert mode editor. (It was just reported yesterday, a fix has already been proposed, and should be published soon.)
When you make any changes to the form markup in expert mode and then save the form the changes appear lost, but actually they are not and if you check the form on the front end it should include such changes.
The problem is that the editor in Expert mode doesn't display the saved form markup, and instead displays what would be the form markup if you switched back to Visual mode.
As I say we should have a fix for this very soon. Keep an eye out for the next Forms update and then test again.
