TH problem

HTML

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css">
<link rel="stylesheet" href="https://unpkg.com/[email protected]/dist/bootstrap-table.min.css">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.15.0/css/all.css">
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js"></script>
<script src="https://unpkg.com/[email protected]/dist/bootstrap-table.min.js"></script>
<script src="https://unpkg.com/tableexport.jquery.plugin/tableExport.min.js"></script>
<script src="https://unpkg.com/@popperjs/core@2/dist/umd/popper.min.js"></script>
<script src="https://unpkg.com/tippy.js@6/dist/tippy-bundle.umd.js"></script>
<div class="container">
<div class="row">
<div class="col-12">
 <button class="btn btn-link aiuto" data-tippy-content="ATTENZIONE: lorem impsum"><i class="fas fa-question-circle"></i></button>

             <table  class="tabella_bordata" id="tab_elenco_manuali" 
                 
  data-toggle="table"
  data-show-columns="true"
  data-show-refresh="true"
    data-height="560"
  data-pagination="true"
   data-page-list="[10, 25, 50, 100, all]"


  
  
  >
      <thead>
        <tr>
          <th></th>
          
       <th id="testa_1" data-sortable=\"true\">Cliente <button class="btn btn-link aiuto" data-tippy-content="ATTENZIONE: lorem impsum"><i class="fas fa-question-circle"></i></button></th>
 <th id="testa_2" data-sortable=\"true\">Preventivo </th>
 <th id="testa_3" data-sortable=\"true\">Preventivo Proforma </th>
 <th id="testa_4" data-sortable=\"true\">Anno </th>
 <th id="testa_5" data-sortable=\"true\">Matricola macchina </th>
 <th id="testa_6" data-sortable=\"true\">Manuali </th>          
          
          
        </tr>
      </thead>
      <tbody>
          
          <tr><td></td><td>Keemun Software srl</td><td> <button class="btn btn-link aiuto"...

JavaScript

tippy(document.querySelectorAll('.aiuto'),{ 
         placement: "top",
          zIndex: 9999,
});