2LIS_02_SCL incorrect qty for EKET-WEMNG

I'm having an issue with extractor 2LIS_02_SCL whereby the quantity field WEMNG is populated incorrectly after perform initialization, below are the activities being done so far:

1) tick BW & NDI options in BF11

2) industry section set to Standard (Core)

3) Transaction key for BW maintained (BWVORG filled up)

4) LBWE activate datasource and included field MCEKET WEMNG (Received)

5) Delete setup table 02, init in OLI3BW

After performing these steps, in RSA3, the qty display in field WEMNG doesn't match with PO schedule line GR qty (in tcode ME23N). In my business scenario, there is a Standard PO with multiple GR raised for single schedule line, and PO is over limit delivery enabled. From ME23N, I can see the GR Qty (under Delivery Schedule tab) is 28 qty, and list of related Material Document can be found in Purchase Order History tab as well. Data also visible in table EKET and EKBE, however, the extractor doesn't able to fetch 28 GR qty during initialization.

Appreciate if anyone could advise on this issue. Thanks.