Hi Corentin,
what is your SAP JCo version loaded into the SAP Adapter?
You might need to update your JCo version to make this work.
Check for newer SAP Adapter Fixes as well.
For the future you should consider upgrading to IS 10.15 instead of IS 10.5 as 10.15 is the last version provided by Software AG.
Starting with the 11.x stream, the webMethods Suite is provided by IBM.
Regards,
Holger