Configuration tester problem when testing Json datasource with wrong Key index

How to reproduce

• Create Datasource that uses Json
• Configure a Elements Connect field with Root element and Json Columns
• Set Key field to the id value that does not exist in the columns
• Run configuration tester

Current result

• In the Configuration tester / Transformed JSON, we can see the evaluation results but NO error to indicate us that value used in the Key field is not correct 
  
   
• In the Configuration tester / Table result Result set we can see only one (first) value. User can't understand why there is only one value here while in the Transformed JSON we have a list of values
  
   

Expected result

• Do the same as if we set the wrong Key field value in the Local SQL datasource: show the message in the Transformed JSON to alert the user that the Key value is not correct.
•