Unable to create device profile without assigning to a username

[kirkeleit]

Running on 1.7.7 with UI 1.7.3.

When I try to create a device profile item the UI will accept input without assigning it to a username, but it does not appear in the list afterwards. If I create a device profile and assign it to a user, it appear in the list.

Is this by design? Username is not a required field and the user manual does not imply that this field needs to be filled.

Thanks for your great work :)