This is standard form behavior being violated, and other forms in our app follow the standard behavior. The user form cannot be submitted with the enter key like these other forms.
 

Expected behavior:
When filling out the user form, after filling out the name of the new user hitting <Enter> submits the form and the user is created.

Actual behavior: Nothing happens at all.
Steps to reproduce:

1. login with an account that can create groups
2. navigate to the users page
3. hit 'create'
4. enter a username and password and password confirmation for the user
5. hit the <Enter> key
6. observe the page does not respond in any way

Note: Tested this with the focus on every form element. None of them produce any behavior from the enter key.