I have noticed a few things that are probably the reason for this behaviour:
1) The Kendo UI Grid is working only with a standard DataSource, not with the HierarchicalDataSource:
2) The editing in the second Grid is not using the correct syntax- editable: "inline"
should be data-editable="inline"
3) It is not recommended both the Grid and the Grid in the details template to have the same dataSource.
4) The Kendo UI Grid does not have a create
events. Please check all of the available events of the Grid:
Additionally, I made a Dojo example demonstrating how to use a Grid with child Grid:
Let me know if you need additional information on this matter.
Telerik by Progress