Your Bluetooth headset might not work if the Bluetooth drivers of Your Bluetooth headset may not work if your system's Bluetooth drivers are out of date or corrupted.
In addition, misconfiguration or services of a stuck Bluetooth device can also cause the error under discussion.
The problem arises when the affected user tries to use his/her Bluetooth headset with the system but he/she can only use the headphones or the speaker but cannot use both at the same time. In this way, you can check your mic by online mic test.
Before moving on with the solutions, make sure your headset is not faulty (try to use it with another device).
Moreover, make sure you are using the latest version of Windows and system drivers (try to use the updated version of the Bluetooth driver from the manufacturer’s website).
Additionally, check if restarting the services (launch services with administrator privileges) related to Bluetooth and system audio solves the issue.
Furthermore, check if selecting the headset from Windows 10 Volume control (right-click on the Volume icon in the system’s tray) solves the issue.