Can you provide more information on your issue? Also, have you tried opening up another form on another list with a people picker control to see if that works. 

Secondly, check that your control on the form is connected to a SharePoint list column or the data will not flow back to SharePoint. 

Thanks,

Eric

I have the exact same problem. None of my person picker fields are being filled or updated when entering a form. Creating a new blank list with a simple picker field also shows this problem.

This is causing major production errors!

@remybosman by default if you add a People Picker column to a Custom List and publish Nintex Forms, the current user will not automatically populate. It will populate as you type in the user manually.

If you would like the People Picker control to auto-populate, please apply the following settings to the People Picker control.

If the issue is related to external user then we would suggest you open a ticket with Nintex support so that you can be notified when the issue has been resolved.

@Erichdb if you are experiencing this issue using external user then this has been reported to Nintex who have an active ticket open with Microsoft.

I would suggest you open a support ticket with Nintex describing the issue and inserting a copy of this post.