Child Grid is not refereshed when paren grid selected record changes

I have added a Parent/Child screen that both parent and child are Grid. When I select the Parent Grid row and insert rows to the child grid are parent/child fields are filled and saved in the child grid properly. However, when I switch from one row to another row in the parent grid, the child grid values are not refereshed. In both parent and child grid, SyncPosition=”True” and Navigate CommitChanges="True" are set to true. Even on the parent grid row selected events, I have add an event handler to referesh the child grid view using command “ApprovalRouteDefaultsView.View.RequestRefresh();” to refresh the Child Grid view but not sure what I missing that it doesnt work. When on the parent child grid I click on the “Refresh” button, it shows the correct data.