title: PXFormula attribute isn't calculating correctly
body: <p>I have a customization to the SalesOrder (SO301000) screen as follows:</p>
  
  <ul>
  <li>I've created a User field on the header section (SOOrder) called 'Total Revenue' (SOOrderExt.UsrTotalRevenue):</li>
  </ul>
  
  <p><a href="https://i.stack.imgur.com/FS3TN.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FS3TN.jpg" alt="enter image description here"></a></p>
  
  <ul>
  <li>I've added a PXFormula attribute to the Ext. Price field in the grid (SOLine.CuryLineAmt) as follows:</li>
  </ul>
  
  <p><a href="https://i.stack.imgur.com/GOU14.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GOU14.jpg" alt="enter image description here"></a></p>
  
  <p>This calculates correctly, until one tries to copy an order to create another order.  When this happens, the value is doubled - as if it's summing the original order PLUS the copied order.  At that point, even if you delete the line item(s) in the copied order, it maintains the summary value in the header.  I have no idea where it would be getting this value.  Have I missed a step?  Is there some type of refresh that I need to add somewhere?</p>