onComplete transform script is not working as expected

Hi,

I am working on Helsinki version of Service Now.

I have a scheduled job which imports data using REST message from some URL and stores in a staging table.

Then I am using a transform map to transform this data into target table.

Here is the issue, I need to delete records from target table which have not been updated from this import.

For this I have given an onComplete() transform form script which should delete unupdated data based on some filter query. but this script is not working as expected. As my understanding it should delete the data matching to filter condition after all the data has been transformed from staging to target table.

inplace of this, this script is deleting data before transformation.

I don't know what is going wrong with this script.