Rad grid with auto generated columns true is in edit mode batch, when click save change, data is lost. 

Datasource Rad grid is datatable programatically. 

You need to make sure that:

• the grid is bound properly to its data source: https://www.telerik.com/support/kb/aspnet-ajax/grid/details/how-to-bind-radgrid-properly-on-server-side
• the custom save button does not do a postback as this will destroy the changes, but invokes the client API of the grid: 
  • example of a custom command item template for batch editing: https://docs.telerik.com/devtools/aspnet-ajax/controls/grid/data-editing/commanditem/command-item-template#custom-commanditemtemplate-for-batch-edit-mode
  • information on handling changes with batch editing: https://docs.telerik.com/devtools/aspnet-ajax/controls/grid/data-editing/edit-mode/batch-editing/server-side-api
  • an example of saving the rest of the page with the batch changes: https://www.telerik.com/support/kb/aspnet-ajax/grid/details/how-to-update-batch-edit-grids-from-outside-button-and-also-save-external-user-input