You are executing a query like below and it returns no data in response even though the employee exists in the SFSF system.
You need to login to the SFSF system and verify if the user you are trying to query is 'inactive' in the system.
For inactive users, this is a standard behavior and they can only be queried using the 'status' filter as per the KBA referred in the 'See Also' section.
inactiver user, user entity, no data in response, api query , KBA , LOD-SF-INT-ODATA , OData API Framework , LOD-SF-INT , Integrations , Problem
SAP SuccessFactors HCM Core 1711