2LIS_11_VAHDR does not show deltas

I activated the data source 2LIS_11_VAHDR and when testing the contents of the data source by using RSA6 and selecting DataSource Extraction Test it gives me 285 rows.

These are rows that were there when I activated it.

However we inserted many more orders, from vbak we see more then 800 records.

It looks like something went wrong with the configuration for the delta, can somebody explain me how to configure the delta for this data source?

Message was edited by:

Cor Slange