DTP not extracting enhanced field data

hello,

I have a custom datasource with enhanced zfields. User-exit was used to populate the zfields.

I loaded full data with DTP and have the option set as "DO NOT EXTRACT FROM PSA".

After checking the data, I found out the zfields were not populated with data and from RSA3 the fields are filled with data. Using full load Infopackage and delta DTP gives the correct data.

Is there a reason why DTP and infopackage extracts are different

bhat