It is a known bug which will be fixed in Syracuse 12.14.0 scheduled for January release.
Workaround is to use SoapUI to test.

Thank you, do you perhaps know How I can get the XML output in soapUI as its generated by the built in tester? I need that exact output for integration development to continue.. The XML output for the in (Developnet -> Web services - > XML) is also not whats required.

Required:

XML VIEW of WS.

I use postman and the requirements are:
WSDL
Basic Authentication
content-type
SOAPAction
Envelope

Thank you so much, was able to get the XML as indicated.

Do you perhaps have an update on the release date for Syracuse 12.14. It seems as if its not available yet.

Thanks in advance.

We don't have visibility of the release date but most probably it will come with the next updates 2022 R2 around April  or May..  Updates are now released every quarter. 

Patch 29 is now out with Syracuse 12.14.0

Thanks for the feedback. I'll download and install and provide feedback.

Thank you everyone that assisted with this issue.