title: Report Builder - merge not available
body: <p>I've created a matrix with row and column groups:</p>
  
  <p><a href="https://i.stack.imgur.com/XVAGb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XVAGb.png" alt="enter image description here"></a></p>
  
  <p>I've started to add a column that will hold data associated with the row groups:</p>
  
  <p><a href="https://i.stack.imgur.com/iwKUQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iwKUQ.png" alt="enter image description here"></a></p>
  
  <p>This has left a gap between the column group labels and the column group data. When I go to merge the cells to bring the column group labels back next to the column group data, the merge option is not available:</p>
  
  <p><a href="https://i.stack.imgur.com/xko5X.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xko5X.png" alt="enter image description here"></a></p>
  
  <p>I take it this is probably by design... but why? I don't see the problem with doing this.</p>