Hi Canto,
Please check whether failed to be clear the document is related to bank charges if so and if you dont define the posting key/rule for the same then that line item will not be clear as set to the status as complete.
or
second possiblity is please check the amount or reference/assignment filed which are correct to clear that document. if it is different from the system's value then system won't be post that entry.
Regards,
Dattatraya Biradar