Paging of gridview not working while using inside other gridview

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C#

ASP

I have a parent Gridview and in each row have a gridview childrent have pagging.

When parent Gridview in pageindex = 0, paging of gridview childrent is working. BUT, parent Gridview have pageindex != 0, paging of gridview childrent not working.

Here is my gridview:

<asp:GridView AllowPaging="true" ID="grvReport">
  <Columns>
    <ItemTemplate>
       <asp:GridView AllowPaging="true" ID="grdDetail" OnPageIndexChanging="grdDetail_PageIndexChanging">
          <Columns>
             <ItemTemplate>
               //Some control
             </ItemTemplate>
          </Columns>
       </asp:GridView>
  </ItemTemplate>
 </Columns>
</asp:GridView>

What I have tried:

protected void grdDetail_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
  GetData(new Pager(int.MaxValue, 0));
  BA_WebGPS.UIL.Controls.GridView grvDetail = (sender as BA_WebGPS.UIL.Controls.GridView);
  int rowIndex = ((GridViewRow)grvDetail.Parent.Parent.Parent).RowIndex;
  GridIndexDetail = rowIndex;
  long vehicleID = long.Parse(grvReport.DataKeys[rowIndex].Value.ToString());
  grvDetail.PageIndex = e.NewPageIndex;
  grvDetail.DataSource = BaseManager.LstFullDataDetail.Where(x => x.VehicleID == vehicleID).ToList();
  grvDetail.DataBind();

}