I have followed below blog to post IDoc in S4.
Cloud connector is working fine.
I am able to post IDoc using SOAP UI but when trying to post the same payload using CPI then getting below error:
org.apache.cxf.transport.http.HTTPException: HTTP response ‘409: input_not_correct’ when communicating with http://s4s.onpr:4400/sap/bc/idoc_xml?sap-client=101
The payload is as below.

Regards,
Shashi