I am trying to update the fields for an item in my document set that uses fields from an External Content List. I can pick them from the Update Item form so they appear to be valid choices. When the workflow runs, the fields show as blank when displayed as a list item. When I click to View Properties, I can see the values I entered displayed. When I try to edit the item, the values are not shown for the External List Item fields, and if I save the unedited form, the values disappear from the View Properties form.
In the attached image, the "811" number is the ID of the External List. I know that is what the External List wants because when I enter them manually I get the display values I want to see.