Call Transfer Issues with Poly CCX500 and Microsoft Teams

[Draxler669]

Hi Guys

I am just about to deploy MS Teams calling across our organisation and I only have one issue to resolve to get there.
For this deployment, I decided to get Poly CCX500 desk phones since I knew that I would have few annoying users asking for a desk phone! BELIEVE ME I DIDNT EVEN WANT TO USE DESK PHONES!!!
The issue is that I dont get the transfer option only on the Poly phones when calls come the main auto attendant.
Please note that the system works fine when I use the mobile app or the desktop app.
Therefore, I think its some sort of device policy that causes the desk phones not get the transfer option only when calls come from main auto attendant.
Desk phones can transfer calls when you call them directly.
Where can I possibly find additional device settings? can this be done achieved using powershell?
I would appreciate it if someone could shed some light on this issue for me. 

[#2]

What version is the phone on?

I had similar issue when I updated the phone to the latest version from the Teams Admin Center (v.5.something).

Had to enabled web server on the handset then connect via the https://IP-address and grab the latest update from the Poly server (v.6.something), which then got the tranfer option back.

Hope this helps.

[#3]

@Laggie 

Latest Firmware release 6.2.21.1198 appear to fix this on initial non-exhaustive testing and can be pushed from Teams Admin