Popup with field editor and reference field won't save (Brooklyn)

FK is a foreign key reference, i.e., there is an integer field in the ControlItem to the entity that holds a list of ControlItem types. (I guess I called these ControlItem’s instead of ControlObj’s. Need to clarify this to make screen shots make sense)

Hopefully, you checked out the tutorial page I referenced, which would help you understand what I’m doing.
Essentially, I have a model called ControlItem that contains all the rows in my ControlItem entity which I connect to a Table object.
The Table object contains a Global Action button that is used for creating and inserting a new ControlItem row. I chose this instead of in-line inserts. This method is outlined in the tutorial page I included.
The last step/action of the Global Action button is to generate a popup with a Field Editor object with a different model called NewControlItem attached to it. In NewControlItem, I have a field called ControlItemTypeID which Display Type is Reference, where the reference information points to an entity called ControlItemType. On the popup screen, the Field Renderer is set up as Picklist where the Option Source is model.
As I mentioned, the picklist shows correctly and, as I mentioned, I have been able to have a Javascrip alert show me that the right value is inserted in the NewControlItem model before the save happens. Here are a few screen shots: