In a Microsoft Skype for Business Server 2015 environment, you update the job title for a user in Active Directory. When the user uses the Skype for Business for Mac or mobile client to join a meeting, the old job title is still shown for the user in the roster of the meeting. However, the contact card shows the correct job title.
This issue occurs because the changes aren't pushed to the Skype for Business server database.
To fix this issue, install the May 2019 cumulative update 6.0.9319.548 for Skype for Business Server 2015 and Unified Communications Managed API 5.0 Runtime and the May 2019 cumulative update 6.0.9319.548 for Skype for Business Server 2015, Web Components Server.
To work around this issue, you can sign in to your account in a Skype for Business for Windows client, and then sign in to the Skype for Business for Mac or mobile client.