It is possible that the phone application cannot transmit calls to your Bluetooth headset unless it is set as the default audio device. Alternatively, this error may be caused by a damaged audio speaker. The problem occurs when a user tries to use a Bluetooth headset with the Your Phone app, but cannot answer a call or hear other people.
Before proceeding with solutions, note that Bluetooth headsets are not yet fully supported by the Your Phone app. Also, check to see if rebooting the devices solves the problem. Also, check that your phone/PC is not paired with another device and that no third-party apps have been used to connect devices via Bluetooth. Also, check that none of the devices are in power save mode. Also, make sure that the “Your Phone” app has access to notifications on the phone and is running in the background on the PC/phone.