I'm also having issues when putting a grid inside the splitter using kendo ASP.NET Core
I'm using the .Content(() =>{ Html.Kendo.Grid<GridViewModel>() .... .Defered( ); }).Defered( ) on the splitter, if I take the code from inside the .Content( ) of the splitter and place it on the page all works as expected?
How can I get a grid inside a splitter ?