Hello!

There is a hidden tab. Need to show this tab and load user control on it within one method.
It is possible to do within two separate calls, but not within a single one.
Here is the code:
Default.aspx
<%@ Page Language="C#" %>
<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>

<script runat="server">
    UserControl currentUC1;
    
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!string.IsNullOrWhiteSpace(CurrentControl.Text))
        {
            this.LoadUserControl(CurrentControl.Text, CurrentControl, currentUC1, Panel1);
        }
    }

    private void LoadUserControl(string num, Hidden hidden, UserControl uc, Ext.Net.Panel targetPanel, bool update = false)
    {
        if (update && uc != null)
        {
            targetPanel.ContentControls.Clear();
        }

        uc = (UserControl)this.LoadControl(string.Format("UserControl{0}.ascx", num));
        uc.ID = "UC" + num;
        targetPanel.ContentControls.Add(uc);
        
        if (update)
        {
            hidden.Text = num;
            targetPanel.UpdateContent();
        }
    }

    private void ButtonShowTab_Click(object sender, DirectEventArgs e)
    {
        ShowTab();

        ButtonShowTab.Disable();
        ButtonLoadControl.Enable();
        ButtonShowTabAndLoadControl.Disable();
    }

    private void ShowTab()
    {
        Panel1.Hidden = false;
        tpControls.Render();
    }

    protected void ButtonLoadControl_Click(object sender, DirectEventArgs e)
    {
        LoadUserControl("1", CurrentControl, currentUC1, Panel1, true);
        
        ButtonLoadControl.Disabled = true;
        X.Msg.Alert("Correct work", "This works as expected. Now reload page and click 'Show Tab AND Load User Control' button.").Show();
    }

    private void ButtonShowTabAndLoadControl_Click(object sender, DirectEventArgs e)
    {
        ShowTab();
        LoadUserControl("1", CurrentControl, currentUC1, Panel1, true);
        
        ButtonShowTab.Disable();
        this.ButtonLoadControl.Disable();
    }

</script>

<!DOCTYPE html>

<html>
<head runat="server">
    <title></title>
</head>
<body>
    <form runat="server">
        <ext:ResourceManager runat="server" />
         
        <h1>Load user control on hidden tab:</h1>
        
        <h3>Two ways to complete:</h3>
        <ol>
            <li>
                Click button 'Show Tab' and then 'Load User Control'. This works as expected
            </li>
            <li>
                Click button 'Show Tab AND Load User Control'. This performs _THE_SAME_ operations as separate buttons, but does not work.
            </li>
        </ol>
        
        <ext:Hidden ID="CurrentControl" runat="server" />
        <ext:Panel 
            runat="server"
            Layout="HBox">
            <Items>
                <ext:Panel runat="server" Layout="VBox">
                    <Items>
                        <ext:Button 
                            ID="ButtonShowTab" 
                            runat="server" 
                            Text="Show Tab"
                            OnDirectClick="ButtonShowTab_Click" 
                            />
                        <ext:Button 
                            ID="ButtonLoadControl" 
                            runat="server" 
                            Text="Load User Control"
                            Disabled="True"
                            OnDirectClick="ButtonLoadControl_Click" 
                            />
                    </Items>
                </ext:Panel>
                <ext:Button 
                    ID="ButtonShowTabAndLoadControl" 
                    runat="server" 
                    Text="Show Tab AND Load User Control"
                    OnDirectClick="ButtonShowTabAndLoadControl_Click" 
                    />
            </Items>
        </ext:Panel>
        <ext:TabPanel runat="server" ID="tpControls">
            <Items>
                 <ext:Panel 
                     Hidden="True"
                    ID="Panel1" 
                    runat="server" 
                    Title="User Controls1" 
                    Width="500" 
                    Height="700"
                    BodyPadding="5">
                </ext:Panel>
            </Items>
        </ext:TabPanel>
    </form>
</body>
</html>
UserControl1.ascx:
<%@ Control Language="C#" %>

<script runat="server">
    protected void HelloFromServer(object sender, DirectEventArgs e)
    {
        X.Msg.Alert("Server", "Hello from server - UserControl №1").Show();
    }        
</script>

<h1>№1</h1>
<ext:Label ID="Label1" runat="server" Text="I am User control №1" />
<br />
<ext:Button ID="Button1" runat="server" Text="User control №1: Ext.Net button" OnDirectClick="HelloFromServer" />
How to reproduce:
Click button 'Show Tab AND Load User Control' - no user control appeares. If two separate buttons 'Show Tab' and 'Load User Control' are clicked, user control appears correctly.

Look forward to hearing from you!
Thanks!