Offline Fairplay not load persistent key data before download metadata

Hi,

we have hls+fps stream, on our app implementation through AVAssetResourceLoader (get spc, generate ckc correctly) and stream played successfully

But when we try to download stream for offline, through session.processContentKeyRequest for contentId, we get spc, generate ckc the same as previously, but can't recieve persistent key data keyRequest.persistableContentKey

PKD failed Error Domain=AVFoundationErrorDomain Code=-11835 "Cannot Open" UserInfo={NSLocalizedFailureReason=This content is not authorized., NSLocalizedDescription=Cannot Open, NSUnderlyingError=0x282da98f0 {Error Domain=NSOSStatusErrorDomain Code=-42668 "(null)"}}

Server and client the same, fps stream played, but not load pkd for offline

All offline part of sources we get from HLS Catalog example, and implement requestCertificate and requestContentKeyFromKeySecurityModule, and i don't understand why we not recieve pkd.