You may not seeing any errors because the operation is set to "Return Application Error Responses:" and the is returning responses similar to:
<message>OBJ: AcctSeed__c - A cash receipt must contain a value for the payment reference field.</message>
which indicates that the data you are sending to the endpoint is not valid.
You can view these documents/responses in the process reporting window by selecting that execution and then selecting the outbound connector.
Typically, when then "Return Application Error Responses:" is checked, users should have a decision shape after the insert/update to check if the insert was successful. If it was not a successful insert, then you can take take appropriate actions like sending out a notification.