Credit Management field CMNUP(Next Check)

Hi Experts,

Field CMNUP (Next Check) in Table VBAK is not updated (BLANK) for few Sales orders. Could any one give me some insight why this field is not updating for SO's.

Dynamic Credit check is Activated and Horizon is 30 days.

Some SO's Delivery date is within Horizon and for Some SO's Outside of Horizon.

Thanks,

Lakshmi Narayana