"Hands-Free AG Audio" outputs audio but "stereo" doesn't

I have a Sennheiser HD 250BT wireless headset. When I connect it to Windows 10 through bluetooth, it shows connected as two different devinces: Hands-Free AG Audio device and stereo device. When I output sound to the HF AG Audio device, I get audio normally, but when I try to output it to the stereo device, I get just silence. Any ideias about this? Also, device manager displays two unknown, driveless devices: Bluetooth Peripheral Device and GAIA. Are those related to the problem? Where can I find drivers for them?

Question by Fernando D'Andrea on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.