Hi Akshay,
When ecc is going upgrade as BW team, we need to take about delta. other wise we will get inconsistency issues like this. Have you done any prerequisites before the ecc upgrade?
Due to the ecc upgrade Extract structure may change. Try to debug the data source at Dev environment and check it. which kind of records its pulling.
Try this option to make correction to your data flow:
Once the migration was over. Reinit your delta and check it. it still its pulls wrong/extra records then raise to SAP.
Thanks
