Missing commitment costs from PO in CN41N

Hello,
when we created purchase order with WBS element assignment, commitment
is visible in report - CN41n, CJI5. After we parked an invoice to this
purchase order, commitment is still visible in reports CN41N. The
problem is - when the parked invoice is changing the status
to "Complete for posting". After this change we don`t see the
commitment in report CN41N.
We also checked the table COOI where we din`t find any values for
commimtment (fields WKGBTR, WHGBTR...).

Thank you for your help

Silvia