Hello Katrin,
The overall status of Contract will be 'Completed' in below 2 condition.
## Condition 1: If all the Contract->Item are with status 'Completed' via 'Reason for Rejection'.
## Condition 2:If , for all the Contract ->Item's the 'Fulfilment Status' is "Finished" + 'Invoice Status'
is "Finished" + 'Validity' of Contract is "Expired".
Hope this explains the behavior.
Best Regards,
Ankush Pashine.