FixedColumns Issue (Extra Spacing)

Hi,

I have an issue with FixedColumns - whenever it is added, it seems to add a slight extra line beneath my last row (see screenshot)

There are a correct amount of <th> and <td> on my table and the table works fine without FixedColumns being added, although once added, this styling issue occurs.

table = $('#tbl_staff_details_stk').DataTable( {
order: [[2, 'desc']],
     scrollX:        true,
     scrollCollapse: true,
     paging: false,
     fixedColumns:   {
           leftColumns: 4
       },
 "bFilter" : false,
  "responsive" : true,
"iDisplayLength": 50,
})

Is it possible to PM my page in question with a login to you guys? That way you'd see the full picture.