title: SSRS Export to Excel does not do expand/collapse of groupings correctly
body: <p>My report works and looks perfectly in the web viewer and looks great in PDF export as well. But when I export to Excel the exported file does not do the groupings correctly. The intent is to have a list of all employees and have their list of accounts underneath that is collapsible. However in Excel the entire report is grouped under one header and it collapses the entire report instead of allowing each header to collapse.</p>
  
  <p>This is the proper way / web viewer:</p>
  
  <p><img src="https://i.stack.imgur.com/emAmG.png" alt="Web Viewer"></p>
  
  <p>But excel is collapsing the entire report not just each header:</p>
  
  <p><img src="https://i.stack.imgur.com/ws6Bw.png" alt="Excel&#39;s view"></p>