There're three reasons below:
1, ACR configuration owner changed; related station “recording owner” changed on Apr 23, but the ACR user does not configure to allow to replay calls for the new owner.
2, Agent does not login; related call happened for station when agent does not login, thus user cannot filter out related recording with the Agent ID but can filter out with the station number.
3, AES product defect which caused ACR cannot get agent information (User will upgrade AES later). Refer to wi00879662 : Agent Information in GetCallInformation is not provided if Service Observer is involved on the call.