Facing problem while using SharePoint SPGridView paging

Hi All,

I am working on SharePoint 2013 Server side development. Today I was trying to bind the data in SPGridView. The things are working fine except one issue. I enabled the grouping in Grid View. This Grouping functionality is working fine for no paging but if I am enabling the Group(ing) functionality then the grouping is not working on page2.

The grouping is working on page 1 but on click of '2' (for page 2) the data shown without group. All the data is OK but it should be in group.

Please find the code snippet below:

Grouping Enabled:

 protected override void OnLoad(EventArgs e)
        {
            oGrid.AllowGrouping = true;         
            oGrid.GroupField = "MainActivities";
            oGrid.GroupDescriptionField = "MainActivities";
            oGrid.GroupFieldDisplayName = "MainActivities";
            oGrid.AllowGroupCollapse = true;

            try
            {
                if (!IsPostBack)
                {
                    DisplayGridBasedOnFilter();
                }
            }
            catch (Exception ex)
            {
throw ex;
             }

        }

//Bind data in grid view control with "oGrid.PagerTemplate = null;"

  private void bindGridControl(SPQuery objSPQuery)
        {
                      
                DataTable table = getSPListItemByQuery(objSPQuery);
                oGrid.PagerTemplate = null;
                if (table.Rows.Count > 0)
                {
                    DataView dataSource = table.DefaultView;
                    dataSource.Sort = "MainActivities";
                    //table.DefaultView.Sort = "MainActivities";
                    oGrid.DataSource = dataSource;               
                    oGrid.DataBind();
        
            }
}
           

//Page indexing

 protected void oGrid_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            try
            {
                oGrid.PageIndex = e.NewPageIndex;
                DisplayGridBasedOnFilter();
            }
            catch
            {
                throw;
            }
        }

Please let me know if any details are required.

Please help.

Thanks.