So at some point in the last few months the headset finally started muting normally with GoToMeeting. I'm not sure if it was Windows updates, GoToMeeting Updates, Pantronincs firmware or what, but it actually works now.
Plantronics Voyager Focus Headset
Macbook Air - High Sierra
GTM Version 8.23.0 Build 8557
Same issue as with others. Headset works perfectly with all other devices and services EXCEPT GTM. When I need to mute I can press the button and it works. However on GTM, I press Mute, "Beep" then it unmutes.
The issue resides with GTM and needs to be addressed
The mute/unmute was working fine for me (although it would have been nice if there was a real integration with GTM) until the last update but now I also have this same issue: whenever I use the Mute button GTM immediatly unmutes me. GTM is the only application doing this.
Current version of GTM is 8.38.1 Build 11282