I have a problem displaying gridview data when combined with displaying time using time control. When the next button is clicked the gridview data does not appear.
<div class="col-md-12">
<!-- Waktu -->
<div class="card text-white box-shadow-0 bg-info">
<div class="card-header pt-1" style="padding-bottom: 0.5rem;">
<h4 class="card-title text-white">
<asp:Label ID="lblKategori" runat="server" Text="Label"></asp:Label></h4>
</div>
<div class="card-content">
<div class="card-body pt-0 pb-0">
<div class="card-text">
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<p>
Sisa Waktu :
<asp:Label ID="lblWaktu" runat="server" Text=""></asp:Label></p>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" />
</Triggers>
</asp:UpdatePanel>
<asp:Timer ID="Timer1" runat="server" Interval="1000" OnTick="GetTime">
</asp:Timer>
</div>
</div>
</div>
</div>
<!--/ Waktu -->
</div>
<div class="col-md-12">
<div class="card rounded-0">
<div class="card-body">
<!--/isi content-->
<asp:UpdatePanel ID="updatePanel2" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:GridView ID="grdTest1" runat="server" AllowPaging="true" Width="100%" AutoGenerateColumns="False"
CellPadding="4" ForeColor="#333333" OnPageIndexChanging="ShowPageCommand" PageSize="1">
<AlternatingRowStyle BackColor="#E6E6FA" ForeColor="Black" Font-Italic="false" />
<HeaderStyle CssClass="HeaderGrid" />
<PagerSettings FirstPageText="First" LastPageText="Last" Mode="NextPrevious" PreviousPageText="Previous"
NextPageText="Next" Visible="False" />
<PagerStyle CssClass="PagerGrid" />
<RowStyle CssClass="IsiGrid" Wrap="TRUE" />
<Columns>
<asp:TemplateField HeaderText="No.">
<ItemTemplate>
<%# Container.DataItemIndex + 1 %>
</ItemTemplate>
<HeaderStyle Width="30px" HorizontalAlign="Center" />
<ItemStyle Width="30px" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Pertanyaan">
<ItemTemplate>
<h5 class="mb-2">
<asp:Label ID="qstn" runat="server" Text='<%#Eval("pertanyaan") %>'></asp:Label></h5>
<asp:RadioButton ID="rad1" runat="server" Text='<%#Eval("pil1") %>' GroupName="A" /><br />
<asp:RadioButton ID="rad2" runat="server" Text='<%#Eval("pil2") %>' GroupName="A" /><br />
<asp:RadioButton ID="rad3" runat="server" Text='<%#Eval("pil3") %>' GroupName="A" /><br />
<asp:RadioButton ID="rad4" runat="server" Text='<%#Eval("pil4") %>' GroupName="A" /><br />
<asp:HiddenField ID="hf" runat="server" Value='<%#Eval("kode_jawaban") %>' />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<br />
<asp:Button class="btn btn-primary btn-sm" ID="btnFirst" runat="server" Text="Awal"
OnClick="btnFirst_Click" />
<asp:Button class="btn btn-primary btn-sm" ID="btnNext" runat="server" Text="Lanjut"
OnClick="btnNext_Click" />
<asp:Button class="btn btn-primary btn-sm" ID="btnPrev" runat="server" Text="Kembali"
OnClick="btnPrev_Click" />
<asp:Button class="btn btn-primary btn-sm" ID="btnLast" runat="server" Text="Akhir"
OnClick="btnLast_Click" />
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnFirst" EventName="Click" />
<asp:AsyncPostBackTrigger ControlID="btnNext" EventName="Click" />
<asp:AsyncPostBackTrigger ControlID="btnPrev" EventName="Click" />
<asp:AsyncPostBackTrigger ControlID="btnLast" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
<br />
<asp:Button ID="btn" runat="server" Text="Submit" OnClick="btn_Click" Visible="false" />
<!--/akhir content-->
</div>
</div>
</div>