Hello Raoul,
This collaboration space if for content and questions related to the SAP Single Sign-On product. It seems that you are not using the SAML IdP we offer with SAP Single Sign-On product but you are using ADFS.
You can post your question in the collaboration space for SAP Fiori or the one for the SAP Web Dispatcher.
In the meantime you can also have a look at the recommended architecture for implementing SAP Fiori using a reverse proxy here:
and also the SAP documentation of the SAP Web Dispatcher solution here:
Regards,
Donka Dimitrova