Upgrade Policy Server to 12.52 SP1 CR08 to solve this issue.
Defects Fixed in 12.52 SP1 CR08
339507 DE157079 SDK Policy API call getAgent fails to find the agent.
https://docops.ca.com/ca-single-sign-on/12-52-sp1/en/release-notes/cumulative-releases/defects-fixed-in-12-52-sp1-cr08