Table form valueCallback strange behaviour
My solution is below. It is a weird solution because It requires small changes.

Define a table value callback.

    $form['links'] = [
      '#type' =&gt; 'table',
      ...
      '#value_callback' =&gt; array($this, 'valueCallback'),
    ];


Implement the callback.

 /**
   * {@inheritdoc}
   */
  public static function valueCallback(&amp;$element, $input, FormStateInterface $form_state) {
    return $input;
  }


The data has structure as it has been sent. So the standard data processing works badly for my case.