Smart Panel OK button doesn't resume the operation from the point routine displayed it

I have added a custom Action Button “CustomApprove” that I press it through an event handler. This action button then displys a SmartP Panel “RoutingPanelDialogData” with OK/Cancel buttons. When user clicks on OK, I expect the method resume from the point displayed the smart panel but when I trace doesn’t hit this point at all. Can some advise what Im doing wrong?

Here is my Event Handler:

        protected void EPApproval_RowInserted(PXCache cache, PXRowInsertedEventArgs e) //, PXRowInserted InvokeBaseHandler)
        {
            //InvokeBaseHandler?.Invoke(cache, e);

            APInvoice document = Base.Document.Current;
            EPApproval approval = e.Row as EPApproval;

            EPApproval approvalPrev = PXSelect<EPApproval,
                        Where<EPApproval.refNoteID, Equal<Required<EPApproval.refNoteID>>,
                        And<EPApproval.status, NotEqual<Required<EPApproval.status>>,
                        And<EPApproval.approvalID, NotEqual<Required<EPApproval.approvalID>>>>>,
                        OrderBy<Asc<EPApproval.approvalID>>>
                        .Select(Base, approval.RefNoteID, EPStatuses.Pending, approval.ApprovalID).LastOrDefault();

            if (document.Status == APDocStatus.PendingApproval && approval.Status == EPStatuses.Pending && approvalPrev.Status != EPStatuses.Routed)
            {
                customApprove.Press();
            }
        }

Here is my Action Button:

        public PXAction<APInvoice> customApprove;
         PXButton(CommitChanges = true, Category = Messages.ApprovalCategory, DisplayOnMainToolbar = true, IsLockedOnToolbar = true)]
         PXUIField(DisplayName = EPMessages.CustomApprove, MapEnableRights = PXCacheRights.Update, MapViewRights = PXCacheRights.Update, Enabled = true, Visible = false)]

        protected virtual IEnumerable CustomApprove(PXAdapter adapter)
        {
            APInvoice document = Base.Document.Current;
            EPApproval approval = Base.Approval.Current;

            if (RoutingPanelDialogData.View.Answer == WebDialogResult.None)
            {
                if (approval != null)
                {
                    RoutingPanelDialogData.Cache.Clear();
                    EPApproval_Extension approvalExt = approval.GetExtension<EPApproval_Extension>();
                    EPRoutingPanelDialogData dialogData = RoutingPanelDialogData.Cache.Insert() as EPRoutingPanelDialogData;

                    dialogData.ApprovalID = approval.ApprovalID;
                    dialogData.Reason = approval.Reason;
                }
            }

            if (RoutingPanelDialogData.AskExt() != WebDialogResult.OK)
            {
                return adapter.Get();
            }

            // When OK button clicked should resume from here but when I trace doesnt hit this. Why?
            EPRoutingPanelDialogData dialog = RoutingPanelDialogData.Current;

            approval = PXSelect<EPApproval,
                    Where<EPApproval.approvalID, Equal<Required<EPApproval.approvalID>>>,
                    OrderBy<Asc<EPApproval.approvalID>>>
                    .Select(Base, dialog.ApprovalID).FirstOrDefault();

            if (document != null && approval != null && dialog != null)
            {
                RouteDocument(document, approval, dialog, EPStatuses.Routed);
            }

            return adapter.Get();
        }

Here is my Smart Panel:

  <px:PXSmartPanel runat="server" Width="600px" ID="RoutingPanelDialogDataSmartPanel" AllowResize="False" LoadOnDemand="True" CloseButtonDialogResult="Cancel" CaptionVisible="True" Caption="Routing Panel New" Key="RoutingPanelDialogData" AcceptButtonID="PXButtonOK" CancelButtonID="PXButtonCancel" AutoCallBack-Enabled="True" AutoCallBack-Command="Refresh" CallBackMode-CommitChanges="True" CallBackMode-PostData="Page">
    <px:PXFormView runat="server" Caption="Routing Panel New" CaptionVisible="False" ID="RoutingPanelDialogDataFormView" DataSourceID="ds" DataMember="RoutingPanelDialogData">
      <Template>
        <px:PXLayoutRule runat="server" StartColumn="True" ID="RoutingPanelDialogDataLayoutRule" />
        <px:PXPanel runat="server" RenderStyle="Simple" ID="RoutingPanelDialogDataPanelParams">
          <px:PXLayoutRule runat="server" StartColumn="True" SuppressLabel="False" LabelsWidth="SM" ControlSize="M" ID="RoutingPanelDialogDataLayoutRuleParams" />
          <px:PXNumberEdit runat="server" Enabled="False" Width="300" CommitChanges="True" DataField="ApprovalID" ID="edApprovalID" Visible="True" />
          <px:PXTextEdit runat="server" TextMode="MultiLine" Enabled="True" Width="300" Height="150" CommitChanges="True" DataField="Reason" ID="edReason" Visible="True" /></px:PXPanel>
        <px:PXPanel runat="server" SkinID="Buttons" ID="RoutingPanelDialogDataPanelButtons">
          <px:PXButton runat="server" Text="OK" DialogResult="OK" CommandSourceID="ds" ID="PXButtonOK" />
          <px:PXButton runat="server" Text="Cancel" DialogResult="Cancel" CommandSourceID="ds" ID="PXButtonCancel" /></px:PXPanel></Template></px:PXFormView></px:PXSmartPanel>