Filtered PV - New Custom Field Not Showing Selected Value

Hello,

I have a screen that I want to limit the PV for. I've read that you can't change the PV for an existing field, so the proper thing to do is create a new one and then pass the selected value to the existing one. I've managed to do that, import the PVREC, and create the stored procedure. That's all working perfectly.

However, the selected value isn't staying in the new custom field (so it's impossible to see what was selected after selecting it). I even tried to put code in to re-populate it (this seems circular to me but it didn't harm anything). Here's the code:

Private Sub cPersonId_0_Chk(ChkStrg As String, retval As Integer)
    MsgBox (ChkStrg)
    Call SetObjectValue("xuser12", Trim(ChkStrg))
End Sub

Private Sub xuser12_Chk(ChkStrg As String, retval As Integer)
    If Left(ChkStrg, 1) = "A" Then
        serr = SetObjectValue("cPersonId_0", Trim(ChkStrg))
        retval = NoAutoChk
    End If
End Sub

The message box fires, but the custom field doesn't get populated.

What am I doing wrong?