Unexpected result when updating the unit price field in an FA through a formula

I made a code to update the Base Documents before the covenants were processed by a request made to facilitate the unit price calculation on the lines based on the current exchange rate. The code works at 98% today something happened and wanted to simulate the situation again and nothing and thought maybe it is an ERP business rule. And you decide to come here to see if anyone could help me. Thanks in advance. Below is the code.

Dim actualizaAvencas As Boolean
Private askForUpdate As Boolean
Dim document As GcpBE900.GcpBEDocumentoVenda

Private Sub EditorAvencas_AntesDeProcessar(Cancel As Boolean, CancelProcessamento As Boolean)

    If Not askForUpdate Then
        'Assign the returned value to check if it is the first time or not (Sim = True and N?o = False)
        actualizaAvencas = PlataformaPRIMAVERA.Dialogos.MostraPerguntaSimples("Deseja actualizar as Aven?as com o c?mbio actual?")

        'Do not ask user again for the next aven?a
        askForUpdate = True
    End If

    If actualizaAvencas Then
        'Get the original doc
        Set document = BSO.Comercial.Vendas.Edita(Avenca.FilialDocOriginal, Avenca.TipoDocOriginal, Avenca.SerieDocOriginal, Avenca.NumDocOriginal)
        ReCalculateAvencas document, GetCurrentExRate()

        'Free the memory
        Set document = Nothing
    End If

End Sub

Public Function GetCurrentExRate() As Double
    'get the last ExRate for Venda
    Dim listaCambioMAlt As StdBE900.StdBELista
    Set listaCambioMAlt = BSO.Consulta("SELECT TOP 1 Venda FROM MoedasHistorico where Moeda = '" & BSO.Contexto.MoedaAlternativa & "' ORDER BY Data DESC")

    'Update the original doc with new Cambio.
    If Not listaCambioMAlt.Vazia() Then
        GetCurrentExRate = CDbl(listaCambioMAlt(0))
     End If

    Set listaCambioMAlt = Nothing

End Function

'===================================
Public Sub ReCalculateAvencas(ByRef Doc As GcpBEDocumentoVenda, ByRef cambioRef As Double)
    On Error GoTo ErrorHandler

    'Set in edition mode
    Doc.EmModoEdicao = True

    'Assign values of CDUs of current line  by matching the CDUs of new added Item
    'update each line.
    Dim counter As Long

    For counter = 1 To Doc.Linhas.NumItens

        'Verify if the first column is an Item instead of a comment lines, acerts, ...
        If Len(Doc.Linhas(counter).artigo) > 0 And HasSpecifiedValueInUSD(Doc.Linhas(counter).artigo) Then

            'Store the USD amount of the current line to by used later in multiple places ...
            Dim prUnitUSD As Double
            prUnitUSD = CDbl(Doc.Linhas(counter).CamposUtil("CDU_PrecoUnitMoedaRef"))

            Doc.Linhas(counter).CamposUtil("CDU_TotalLiqMoedaRef") = Doc.Linhas(counter).Quantidade * prUnitUSD
            Doc.Linhas(counter).PrecUnit = cambioRef * prUnitUSD

        End If
    Next counter

    'Update cambio of the header
    If Doc.Moeda = BSO.Contexto.MoedaAlternativa Then
        Doc.Cambio = cambioRef
    Else
        Doc.CambioMAlt = cambioRef
    End If

    'Update the document after update its lines.
    Dim msg As String
    BSO.Comercial.Vendas.Actualiza Doc, msg

    'Update aven?a value with new calculated original doc
    Avenca.EmModoEdicao = True
    Avenca.Valor = Doc.TotalDocumento

    Exit Sub
ErrorHandler:
    PlataformaPRIMAVERA.Dialogos.MostraAviso "Erro!", PRI_Informativo, msg & vbNewLine & Err.Description
End Sub

Private Sub EditorAvencas_AvencaIdentificada(TipoProcessamento As Integer, Cancel As Boolean)
    askForUpdate = False
End Sub

'=======
Function HasSpecifiedValueInUSD(ByVal artigo As String) As Boolean
    'Updated If it has specified price in USD
    Dim prUnitUSD As Double
    prUnitUSD = CDbl(BSO.Comercial.Artigos.DaValorAtributo(artigo, "CDU_PvPMoedaRef"))

    If prUnitUSD <> vbNull And prUnitUSD > 0 Then
        HasSpecifiedValueInUSD = True
    Else
        HasSpecifiedValueInUSD = False
    End If

End Function

What happened was the exchange rate is 60 and in the first document (FA) to be generated from the base document (FP) it seems that the change was considered to be 62.42 and I do not understand how this could have happened .

Thenormalbehaviorinanotherdocumentwhereeverythingwentwell.