2 AJAX ModalPopupExtender pointing to single PopupControlID not working. ?

ASP.NET / VB.NET 2017 webform / AJAX toolkit

I have a panel that needs to display when either of 2 SVG circles are clicked.  I don't want to have the exact same code twice with the only difference being the Panel ID.  So I have 2 ModalPopupExtenders with a different TargetControlID on each (circle), but both pointing to the same PopupControlID.

The code is below.   If I comment out either one of the <ajaxToolkit:ModalPopupExtender /> code sections, the other one works just fine.   But when both code sections are active, clicking on either TargetControlID circle results in the web page darkening (normal) and the modal popup never appears.

What am I doing wrong?

Thanks,

        <ajaxToolkit:ModalPopupExtender 
                ID="mpeMfgPopupStart" 
                runat="server"            
                TargetControlID="circle5"
                PopupControlID="panMfgPopup"
                BackgroundCssClass="modalBackground"
                DropShadow="True"
                CancelControlID="btnMfgClose">
        </ajaxToolkit:ModalPopupExtender>


        <%-- I need 2 TargetControlID that execute the same Popup.  Just copy one and change the ID and TargetControlID --%>
        <ajaxToolkit:ModalPopupExtender 
                ID="mpeMfgPopupComplete" 
                runat="server"            
                TargetControlID="circle6"
                PopupControlID="panMfgPopup"
                BackgroundCssClass="modalBackground"
                DropShadow="True"
                CancelControlID="btnMfgClose">
        </ajaxToolkit:ModalPopupExtender>

        <asp:Panel ID="panMfgPopup" runat="server" CssClass="modalPopupMfg" style="display:none; background-color: #F7F7F7"> 

            <asp:UpdatePanel ID="UpdatePanelMfg" runat="server">
              <ContentTemplate> 

                <div class="header">
                    <asp:Label ID="lblMfgTitle" runat="server" Text="MANUFACTURING"></asp:Label>
                </div>
                <div class="body">
                    <table id="Manufacturing" width="100%" border="0" cellpadding="10" cellspacing="0" class="tbl_order_header">


                           The content code...


                    </table>
                </div>
              </ContentTemplate>
            </asp:UpdatePanel> 

            <hr style="border-top: 1px solid #EDEDED; background: transparent; width:690px"/>

            <div class="footer" align="right">

                <asp:Button ID="btnMfgClose" runat="server" Text="X" OnClick = "MfgClose_Click" Width="100px" Height="24px" BackColor="#EDEDED" ForeColor="#333333" Font-Bold="True" Visible="True" />
            </div>
            
            <ajaxToolkit:DragPanelExtender ID="DragPanelExtenderMfg" runat="server" TargetControlID="panMfgPopup" />

        </asp:Panel>

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