i have a Voyager Legend UC, Voyager 4300 UC and Calisto 5300. They appear to have the same issue.
When the device is connected to the laptop (Windows 10) with the dongle (BT300 or BT600), all softphone functions work fine, including volume +/- and mute. The mute is also synced with MS Teams. But I can never pick up or end MS Teams phone calls. When Teams is ringing, and I press the Teams button on the device, it will prompt with "answering call", but it doesn't actually pick up. I've called Poly Support but they could only assume it's a PC compatibility issue without any solution. Has anyone encountered this issue?