Filter in Delta Mode

Hello together,

if you are common with sap bw you migh can answer this easy

we are using a 3rd party tool to extract data via SAP-standard api.

however im facing the problem that filters work fine in init mode, but not in delta mode.

looks like filters are stored in Table ROOSPRMSF in init mode and only used for init extractions.

when calling the z-datasource FM-Routine filters are not passed to I_SELECT parameter.

is this a standard SAP-behaviour, or should filters also work for Delta-Extractions?

Regards

Stefan Seeburger