Powermax RestAPI , Set policy based snapshot persistent

Hello ,

Based on the offical RestAPI interface , i send a request like below to powermax , but got an error response , can anyone help to explain what is the problem, thanks !

request method: PUT

request url: univmax/restapi/92/replication/symmetrix/0004979000XX/storagegroup/SG_XXXX/snapshot/DailyDefault/generation/2

request body:{"executionOption":"SYNCHRONOUS","action":"Persist","persist":{"persist":true}}

response:500 , message: "Unable to calculation task for action Persist"

Seems this method is not support .

powermax version: 5978.711.711

unisphere version:9.2