A based basic routing integration from REST to SOAP result on runtime in javax.xml.soap.SOAPExceptio

Summary

How to define/setup a REST/SOAP based basic routing integration that runs successfully

Content

Hereby my (faied) scenario

I am able to call an external SOAP based WSDL with SOAPUI with a pre-provided un/pw and receive the expected answers

I am able to define, test and validate a connection based on this external wsdl using TLSv1.1 and enabling security (basis authN) with the pre-provided un/pw

I am able to define an integration using a REST based trigger connection and SOAP based invoke connection

On runtime the execution of this integration result in javax.xml.soap.SOAPException: Not a valid SOAP Content-Type: text/html;