Bloomberg Add-In in Excel: Issue with BDP Function Not Refreshing Cells

Question

I'm currently using the Bloomberg add-in in Excel and utilizing the BDP function.
I want to automate a process where, upon changing the selection in a dropdown list, the cells in the sheet that depend on this selection will refresh accordingly, and then output the sheet to a PDF file.
This process should repeat for each item in the dropdown list.
While there's no issue with Excel's general functions, I've encountered a problem where the cells don't refresh when I change the selection in the dropdown list if they are using the BDP function.

Could someone advise on how to ensure the cells refresh when using the BDP function in this context?

Option Explicit
Sub printPDF()
    Dim ws As Worksheet
    Dim validationCell As Range
    Dim validationFormula As String
    Dim saveFolder As String
    Dim pdfName As String 
    Dim item As Variant
    Dim dropdownValues As String
    
        
    Set ws = ActiveSheet
    Selt validationCell = ws.Range("AF1") 'location of pulldown list
    validationFormula = validationCell.Validation.Formula1
    
    'path
    savFolder = ws.Range(A1)
    If Right (saveFolder, 1) <> "\" Then
        saveFolder = saveFolder & "\"
    End If
    
    If Left(validationFormula, 1) = "=" Then
        Dim listRange As Range
        Set listRange = ws.Evaluate(Mid(validationFormula,2))
        ReDim dropdownValues(listRange.Cells.CountLarge - 1)
        Dim i As Long
        i = 0 
        Dim cell As Range
        For Each cell In listRange
            dropdownValues(i) = cell.Value
            i = i+1
        Next cell
    End If
    
    If UBound(dropdownValues) >= 0 Then
        validationCell.Value = dropdownValues(0)
    End If
    
    Application.Calculation = xlCalculationAutomatic
    For Each item In dropdownValues
        'change pull down
        validationCell.Value = item
        Application.Calculate
        'wait
        Do While Application.CalculationState <> xlDone
            DoEvents
        Loop
        
        'Name of PDF
        pdfName = ws.Range("AF2").Value & "_" & Format(Now, "yyyymndd_hhamss")
        'Save as PDF
        ws.ExportAsFixedFormat Type:=xlTypePDF, Filename:=saveFolder & pdfName & ".pdf", quality:=xlQualityStandard
    Next item
    MsgBox “Done”
    Shell "explorer.exe """ & saveFolder & """", vbNormalFocus
End Sub