title: Calculate formula in closedxml
body: <p>I used a formula in closedxml:</p>
  
  <pre><code>var result = worksheet.Cell(3, 8);
  result.FormulaA1 = "=IF(ISNA(VLOOKUP(G3,OrganizationUnitsById,2,FALSE))," 
                   + "" 
                   + ",VLOOKUP(G3,OrganizationUnitsById,2,FALSE))";
  </code></pre>
  
  <p>When I used this formula before, it worked perfectly. But then I changed something, then this formula didn't calculate automatically. I saved file from an application, this formula works but didn't calculate automatically.</p>
  
  <p>What is wrong?</p>