you have to define priority for every column

            "columnDefs": [
                {
                    "targets": [0],
                    responsivePriority: 1,
                },
                {
                    "targets": [2],
                    responsivePriority: 3,
                },
                {
                    "targets": [3],
                    responsivePriority: 4,
                },
                {
                    "targets": [4],
                    responsivePriority: 5,
                },
..
..
..