SCIM Improper schema error with PATCH

Hello,

I am doing first tests with the Salesforce SCIM API (which isn't documented that great, unfortunately). I got the basic GET calls running, but when i try to modify a user i get an "Improper Schema" error.

Any idea what could be wrong?

PATCH https://{orgurl}/services/scim/v2/Users/{id}

Body:

{

    "schemas": [

        "urn:ietf:params:scim:schemas:core:2.0:User",

        "urn:ietf:params:scim:schemas:extension:enterprise:2.0:User"

    ],

    "userName": "insightssecurity@00d1t0000001za8eaa.com",

    "alias": "test"

}

Response:

{

    "schemas": "[\"urn:ietf:params:scim:api:messages:2.0:Error\"]",

    "detail": "Improper Schema.",

    "status": 400

}

Note that, when using PUT, a slightly augmented version of the request (added some fields that the server regards as required) works but the same body fails when used in PATCH.

{

    "schemas": [

        "urn:ietf:params:scim:schemas:core:2.0:User",

        "urn:ietf:params:scim:schemas:extension:enterprise:2.0:User"

    ],

    "userName": "insightssecurity@00d1t0000001za8eaa.com",

    "displayName": "Security User",

   "name": {

        "formatted": "Security User",

        "familyName": "User",

        "givenName": "Security"

    },

    "alias": "Test",

    "active":true,

    "emails": [

        {

            "type": "work",

            "primary": true,

            "value": "insightssecurity@example.com"

      }

    ],

    "entitlements": [

        {

            "value": "00e1t000000FPtnAAG",

            "$ref": "/Entitlements/00e1t000000FPtnAAG",

            "display": "Analytics Cloud Security User",

            "type": "Profile",

            "primary": true

        }

        ]

}

Thanks

Thomas