Deserialization of xml failed via transformation GetEntitySet

Hi experts

i'm implementing a SAPUI5 app, which should get some imformations from ECC side.

To do this, i've implemented a service which is working fine only for GetWEntity method:

/sap/opu/odata/sap/zfiori_read_orders_srv_02/EtOrdersSet('40504*')

I've set the service also for the GetEntitySet method, but the transformation which should deserialize the XML is failing.

calling the service in this way:

/sap/opu/odata/sap/zfiori_read_orders_srv_02/EtOrdersSet?$filter=Vbeln eq '4050344*', transformation get only the 5th char of the string, and in parameters i found VBELN = 0000040503.

The transformation is perfomed in this method:

/IWBEP/CL_MGW_REMOTE_HANDLER==CP   method DESERIALIZE_REQUEST.

DATA: lo_xml_reader  TYPE REF TO if_sxml_reader.

   IF iv_request_data IS NOT INITIAL.

     lo_xml_reader = create_xml_reader( iv_request_data ).

     CALL TRANSFORMATION id

        SOURCE XML lo_xml_reader

        RESULT     context        = es_request_context

                   entity         = ev_entity_data

                   model_id       = ev_model_id

                   language       = ev_language

                   text_keys      = et_text_keys

                   technical_name = ev_vocab_id

                   version        = ev_version.

   ENDIF.

Any help?

Best regards

Marco