I have the same question posed in this previous thread, but the solution hasn't worked for me. https://answers.microsoft.com/en-us/msteams/forum/all/double-beep-when-muted-on-teams-aftershokz/d67018d1-7081-4acf-b688-bf947a524058?page=1
In short, no matter how I try to mute my mic, the headset tells me mute is on and double-beeps every few seconds. It happens if I mute the call, mute in call settings, or even if I simply mute in my laptop's sound settings.
Teams does NOT alert me that I'm muted if I use a different headset or no headset -- only using the Aftershokz headset. This is an Aftershokz problem, not a Teams problem, but Aftershokz tech support has been unhelpful. I'm hoping someone here has a workaround.
This problem cropped up last fall, went away, and now is back.