Hi Honey,
Check the clearing date and time of the payment document which cleared the open Items.
It might happen that the dunning happened before and generated the dunning letter, where as payment document was posted later to the account.
In normal scenarios, these happens for payments which are being re-allocated from the payment clarification worklist (CWL). So even if the customer has paid within the due date, the payment has not actually cleared the Open items on the due date, as it is sitting in the Payment CWL.
Once it is posted to the account, only then the clearing happens and Dunning process is triggerred based on the open items in the customer account.
Now, if you are not able to see any dunning procedure or dunning level updated in FPL9 for the account, it might happen that the dunning has been reversed.
You can check the field (FKKMAKO-XMSTO) for the particular account.If it has a flag X, then the dunning has been reversed.
Hope it helps in explaning your query..
Thanks,
Amlan