Cannot get voicemail working for Skype for Business online users with on-prem exchange
We have a Skype for Business Hybrid deployment using our on-premises exchange 2013 servers to host the voicemail via UC.
If the user is on-premises the Skype Client (windows), Mobile app and Polycom phones work fine. If the user is online, then the Skype Client (windows), Mobile app work fine with voicemail but the physical Polycom phone does not.
The problem I am having is, when you press the voicemail button on the Polycom you get “Sorry a system error occurred” – it looks to call the users SIP address with a voicemail attribute – I assume Skype is then meant to forward it to the Exchange UM Subscriber SIP address.
If I call the Subscriber Access SIP address directly from the Polycom it you can access the voicemail by navigating the audio driven menu.
Software Verison: 5.9.1.0615
Handset Model: VVS 410
I am struggling to find the MS setup instructions for Skype for Business Hybrid cloud users and on premises Exchange UM.
I have been following the link below but find lots of detail is missing so I am sure I have missed something