Values added on the XDataServer aren't being returned

And about what values are talking about here?

  1. What is the FBatchId value before the Post?
  2. What is the BatchId value in the request JSON body sent to the server?
  3. What is the TSalesSheet(Entity).BatchId value received in the server?
  4. What is the FBatchId value in the AfterApplyUpdates event?