After working on an issue for about half of a year now and finally finding a workaround for it I wanted to share it with anyone else who might also be having the same issue. Currently there is a known bug within the Skype for Business UI that does not allow users to transfer calls to other phone numbers or voicemail listed on someone’s contact card.
For example, if I was to receive a call, and wanted to transfer the call directly to one of my co-worker’s voice mail, normally you would initiate a transfer, search for the recipient, and right click their name to get a list of alternate call options from their contact card:
When you select Voice Mail or any other number listed the client does nothing.
A workaround for this issue is to force the Lync 2013 UI for the user with a client policy. Then this functionality still works: