3546816 - Error "Invalid filter value." seen when trying to retrieve users starting with "XXX"

The following error occurs while sending a GET request to the Identity Provisioning proxy system API when trying to retrieve users with username's starting with "XXX":

https://<tenand_ID>.accounts.ondemand.com/ipsproxy/service/api/v1/scim/<IPS_Proxy_system_ID/Users?filter=userName sw "XXX" 

Response:

{    "schemas": [        "urn:ietf:params:scim:api:messages:2.0:Error"    ],    "detail": "Invalid filter value.",    "status": 422}

• SAP Cloud Identity Services
• Identity Provisioning

Identity Provisioning, proxy, filter, GET, users, postman, invalid filter , KBA , BC-IAM-IPS , Identity Provisioning Service (IPS) , Problem