Dropdown list depends on other Dropdown list in IE and doesn't update vba

Question

I'm using VBA to automate IE. I have two dropdown lists (let's call them "A" and "B"). The B list depends on the values of the A list, so the B list won't show its values unless I select the A list value manually first. I tried with this:

 Sub pifa ()

      Dim ie As Object
      
      Set ie = CreateObject("internetexplorer.application")
      
      With ie
          .Visible = True
          .navigate "https://serviciosjava2.pifa.gob/rcel/jsp/index_bis.jsp"

           Do While .Busy
               DoEvents
           Loop

           Do While .readyState <> 4
                DoEvents
           Loop
           
                ie.document.getElementById("puntodeventa").Value = "31" 'A list value

           Do While .Busy
               DoEvents
           Loop

           Do While .readyState <> 4
                DoEvents
           Loop
           
                ie.document.getElementById("universocomprobante").Value = "19" 'B list value (doesn't work)
      
      End with

 End sub

For the A list value everything is OK, it changes the dropdown list value correctly, but as I didn't actually clicked manually the value, the B list won't update and show the values. I also tried this, and doesn't work:

 ie.document.getElementById("puntodeventa").Click 'A list value

"A" list code:

<select name="puntoDeVenta" onchange="actualizarDescripcionPVConDelay(this.selectedIndex);ajaxFunction();" id="puntodeventa">
        <option value="" selected="selected" style="color:#888;" onclick=document.getElementById("desc_pto_vta").innerHTML="";>seleccionar...</option>
                        
        <option value="31">&nbsp;puntodeventaseleccionado</option>
                        
</select>

"B" list code:

 <select name="universoComprobante" onchange="actualizarDescripcionTC(this.selectedIndex);" id="universocomprobante">
        <option value="" selected="selected" style="color:#888;">seleccionar...</option>
                        
        <option value="10">Factura A</option> 'this appears when I click manually the A list

        <option value="19">Factura B</option> 'this appears when I click manually the A list

                        
</select>

Answer 1

I solved it by adding this below the value entrance:

 ie.document.getElementById("puntodeventa").FireEvent ("onchange")