title: [SymmetricDS]: Transform using PK insert duplicate data
body: <p>I have a table physical PK is ID (identity) at both sides. During sync, I manually add transform column to </p>
  
  <p>ID - remove, pk: 0</p>
  
  <p>Num - copy, pk: 1</p>
  
  <p>DateTime - copy, pk: 1</p>
  
  <p>I think Num and DateTime would serve as virtual PK for symmetric to find which row to update/delete. My transform have UpdateFirst = 1</p>
  
  <p>But in my target table, I get 2 record with same Num and DateTime (ID is different).</p>
  
  <p>This only  happen to one of my table, other tables with same setting are working fine. I just like to know how it can happen ?    </p>