Link to test case: https://datatables.net/examples/server_side/post.html
Description of problem:

After skimming through a bunch of the examples I've narrowed down the problem to what seems to be "server-side":

1. All "server-side" examples initially render datatables <th> and <td> elements without dt-type classes. The initial alignment is therefore incorrect.
2. If the user sorts one of the columns, the <th> element will get a dt-type class, but the corresponding <td> elements will not, therefore leading to a visually worse misalginment between header and colums cells.

Let's take 2 examples, one "server-side" and one other one type, where we will both look at the Salary column.

• "POST"

  • Here on first load we can see that the <th> element for the Salary field has classes dt-orderable-asc dt-orderable-desc. The <td> elements under this column have no classes.
  • If we start to sort the column once, we see that <th> element has the classes dt-orderable-asc dt-orderable-desc dt-type-numeric dt-ordering-asc, but the underlying <td> element only has a sorting class sorting_1.
  • The result: misalignment between <th> and <td> elements for this column.

• "AJAX data source arrays"

  • Here on first load we can see that the <th> element for the Salary field has classes dt-orderable-asc dt-orderable-desc dt-type-numeric. The <td> elements under this column havedt-type-numeric` classes.
  • If we start to sort the column once, we see that <th> element has the classes dt-orderable-asc dt-orderable-desc dt-type-numeric dt-ordering-asc, and the underlying <td> element have dt-type-numeric sorting_1 classes.
  • The result: correct alignment between <th> and <td> elements for this column.

I hope this is enough information to further debug the problem.