Generic extractor with delta capable is behaving like full update or Init

Hi Experts,

I have one generic extractor (ZSFPC_EXP_ITEM) with function module, this extractor is working fine when i run full or initialization, but when i trigger delta update then extractor bringing all the records (i mean equal to initialization records), this extractor is not bringing the changed or created records since last init or delta update date.

we are using Generic delta field as CPUDT(Created on date) , type is Calday, Safety interval lower limit is '0' days.

In ROOSOURCE table delta is AIE (After-Images Via Extractor (FI-GL/AP/AR)).

Please let me know what could be the issue and how to resolve this issue.

Regards

Raja.