In a Microsoft Skype for Business Server 2015 environment, consider the following scenario:
You set the Busy Options feature to Busy on Busy or Voicemail on Busy status by using the Set-CsBusyOptions cmdlet.
You verify that the Busy Options is turned on by using the Get-CsBusyOptions cmdlet.
You sign in to the Skype for Business for iPhone or Android client. Or, you sign in to the Skype for Business client by using a third-party phone device such as Polycom, Spectralink and so on.
You turn on the Call Forwarding.
You run the Get-CsBusyOptions cmdlet to check the Busy Options status.
In this scenario, you can see the Busy Options settings that you set before are lost.
To fix this issue, install the January 2019 cumulative update 6.0.9319.537 for Skype for Business Server 2015, Core Components.
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