Additional features, settings, or issues not covered by specific Microsoft Teams categories
I have the same issue with the Plantronics 8220 headset. I press mute in Teams, it mutes for a blink and then it unmutes. So I can't mute in Teams meetings. I have changed the mic to my notebook mic and everything works fine in Teams. So the problem only occurs with the Plantronics headset.
So I tried some other setting, but nothing worked except for one thing... when you close your Plantronics Hub software everything works fine!
The issue is probably in the last version of the Plantronics Hub software. The version I have currently, that has the mute/unmute issue, is 3.23.0 Build 34198.