After you call a mobile phone number in Skype for Business 2016, the recipient information is incomplete in the call history. In Skype for Business 2016 conversations, the call appears under the caller's identity. However, the picture and the contact card may correspond to the call recipient. In the Outlook conversation history, the destination field of the history message includes only the caller's identity, but the call recipient's identity may appear in the subject and body of the message.
To fix this issue, install the October 10, 2017, security update for Skype for Business 2016 (KB4011159).