[Resolvido] Problemas paginação Codebehind C#

A paginação é escrita perfeitamente, mas a navegação não funciona e não encontro onde está o erro. Se puderem me ajudar.

List.aspx

<asp:GridView runat="server" PageSize="2" AllowPaging="true" ID="gvSession"
OnRowCommand="List_Commands"
CssClass="table-list"
AutoGenerateColumns="false"
AlternatingRowStyle-CssClass="dark"
OnDataBound="gvSession_OnDataBound"
OnRowDataBound="gvSession_OnRowDataBound"
OnPageIndexChanging="gvSession_OnPageIndexChanging"
EnableViewState="true">

	<Columns>
 <asp:TemplateField>
 <HeaderTemplate>
 <input type="checkbox" />
 </HeaderTemplate>
 <ItemTemplate>
 <asp:CheckBox ID="chbSelect" runat="server" />
 </ItemTemplate>
 </asp:TemplateField>
 <asp:TemplateField HeaderText="Nome da Sessão">
 <ItemTemplate>
 <asp:Label ID="lblSessionName" runat="server"></asp:Label>
 </ItemTemplate>
 </asp:TemplateField>
 <asp:TemplateField HeaderText="Sub-Sessões">
 <ItemTemplate>
 <asp:PlaceHolder ID="phSubSessions" runat="server"></asp:PlaceHolder>
 <asp:Label ID="lblSubSessions" runat="server"></asp:Label>
 </ItemTemplate>
 </asp:TemplateField>
 <asp:TemplateField HeaderText="Data de Criação">
 <ItemTemplate>
 <asp:Label ID="lblDateRegister" runat="server"></asp:Label>
 </ItemTemplate>
 </asp:TemplateField>
 <asp:TemplateField HeaderText="Tipo de Sessão">
 <ItemTemplate>
 <asp:Label ID="lblSessionType" runat="server"></asp:Label>
 </ItemTemplate>
 </asp:TemplateField>
 <asp:TemplateField HeaderStyle-Width="120" HeaderText="Ações">
 <ItemTemplate>
 <asp:ImageButton ID="ibView" CommandName="CmsView" ImageUrl="../../app_image/icon/btn-view.png" runat="server" />
 <asp:ImageButton ID="ibEdit" CommandName="CmsEdit" ImageUrl="../../app_image/icon/btn-edit.png" runat="server" />
 <asp:ImageButton ID="ibDelete" OnClientClick="java script: return confirm('Tem certeza que deseja deletar este item?');" CommandName="CmsDelete" ImageUrl="../../app_image/icon/btn-delete.png" runat="server" />
 <asp:ImageButton ID="ibApprove" OnCommand="List_Commands" CommandName="Approve" ImageUrl="../../app_image/icon/btn-approve.png" runat="server" />
 </ItemTemplate>
 </asp:TemplateField>
	</Columns>
	<PagerTemplate>
 <div class="pagination">
 <div class="float-left">
 <asp:ImageButton ID="ImageButton1" ImageUrl="../../app_image/btn/btn-excluir-selecionados.png" runat="server" />
 <asp:ImageButton ID="ImageButton2" ImageUrl="../../app_image/btn/btn-aprovar.png" runat="server" />
 </div>
 <div class="float-right">
 <asp:PlaceHolder ID="PagingNum" runat="server"></asp:PlaceHolder>
 </div>
 </div>
	</PagerTemplate>
</asp:GridView>

protected void gvSession_OnDataBound(object sender, EventArgs e)
{

 GridViewRow gvr = gvSession.BottomPagerRow;

 if (gvr == null) return;

 PlaceHolder phPager = gvSession.BottomPagerRow.FindControl("PagingNum") as PlaceHolder;

 if (phPager != null)
 {
 if (gvSession.PageIndex > 0)
 {
 phPager.Controls.Add(new LiteralControl("<div class='float-left'>"));
 ImageButton btnPage = new ImageButton();
 btnPage.ImageUrl = "~/app_image/btn/btn-voltar.png";
 btnPage.CommandName = "Page";
 btnPage.CommandArgument = "Prev";
 btnPage.ToolTip = "Página Anterior";
 phPager.Controls.Add(btnPage);
 phPager.Controls.Add(new LiteralControl("</div>"));
 }
 phPager.Controls.Add(new LiteralControl("<div class='content'>"));
 for (int i = 0; i < gvSession.PageCount; i++)
 {
 int PageNumber = i + 1;
 if (i == gvSession.PageIndex)
 {
 Label lbPage = new Label();
 lbPage.Text = "[" + PageNumber.ToString() + "]";
 lbPage.CssClass = "page-index";
 phPager.Controls.Add(lbPage);
 }
 else
 {
 LinkButton lbPage = new LinkButton();
 lbPage.CommandName = "Page";
 lbPage.CommandArgument = PageNumber.ToString();
 lbPage.ToolTip = "Ir para a página " + PageNumber.ToString();
 lbPage.Text = PageNumber.ToString();
 phPager.Controls.Add(lbPage);
 }
 }
 phPager.Controls.Add(new LiteralControl("</div>"));
 if ((gvSession.PageIndex+1) < gvSession.PageCount && gvSession.PageCount > 1)
 {
 phPager.Controls.Add(new LiteralControl("<div class='float-left'>"));
 ImageButton btnPage = new ImageButton();
 btnPage.ImageUrl = "~/app_image/btn/btn-avancar.png";
 btnPage.CommandName = "Page";
 btnPage.CommandArgument = "Next";
 btnPage.ToolTip = "Próxima Página";
 phPager.Controls.Add(btnPage);
 phPager.Controls.Add(new LiteralControl("</div>"));
 }
 }
 }
 protected void gvSession_OnPageIndexChanging(Object sender, GridViewPageEventArgs e)
 {
 gvSession.PageIndex = e.NewPageIndex;
 }
 protected void binder()
 {
 gvSession.DataSource = CmsSession.Select(LoggedUser.Client);
 gvSession.DataBind();
 }
 protected void Page_Load(object sender, EventArgs e)
 {
 VerifyLogin();
 }
 protected override void OnLoadComplete(EventArgs e)
 {
 base.OnLoadComplete(e);
 binder();
 }