I believe this is expected behavior. However, leaving off in the Document Properties dialog after attempting above steps, create a new Axonometric grid, and then undo and redo that — the dialog will not update to display the new grid then.
I believe this is expected behavior. However, leaving off in the Document Properties dialog after attempting above steps, create a new Axonometric grid, and then undo and redo that — the dialog will not update to display the new grid then.