InfoPath Dev

I am having a problem that is driving me insane, since I am using the same approach in quite a few other InfoPath forms (in the same site collection) without problems:

I need to set a Person Picker to a specific person. For demonstration purposes I put the following three steps on a button where I set the DisplayName, AccountID and AccountType. But the person picker does not reflect the values.

The interesting thing is that as soon as I manually chose a person and then click on the button it works and displays the person that I am trying to set with the button. It also works when I then delete the Person Picker and then click on the button again.

It just does not work when the form opens and the Person Picker field is empty.

I have been trying many different approaches. I compared the configuration of other InfoPath forms with the same logic as well as the configuration of the field in SharePoint (BTW it is SharePoint Online on Office 365). Just to make sure I deleted the field in SharePoint and then in InfoPath and started all over again. No difference.

 Does anyone have an idea what might be causing this? 

Is there any chance at all that the repeating "Person" group is not included by default? If you look at the Data tab in the ribbon and open Default Values, you can find it and make sure it is checked. Sometimes you have to also check the defaults on a repeating section / table if the people picker is in there.

Dear Hilary,

thank you for the response.

I checked and everything is checked, so this unfortunately can't be the reason.