Thank you for the update.
We have analyzed your query with your sample application. In that you have used TemplateColumn without MappingName in SecondPage.xaml. Hence the binding exception occurred when reload the page. In SfDataGrid we must give a MappingName when creating the column. We have modified the sample by setting a MappingName in TemplateColumn and please find the sample under the following location.
Please let us know if you need further assistance.
Jai Ganesh S