The kendo grid's keyboard navigation does not work reliably when rendering a grid inside a dialog. I assume that this is caused by the dialog's focus trap.
To reproduce the issues, open this DOJO that just renders a grid in a dialog.
-> the close button of the dialog is focused
Also note that after reloading the DOJO and doing this for the first time, step 3 directly focuses the checkbox while in consecutive runs, the cell is focused.