Windows – How to play android phone audio on a windows 8.1 PC’s speakers using bluetooth, when “just connecting” doesn’t work

This question has been answered before here, here, and here. All answers say that it basically just works when you pair the android phone with the windows PC and hit play on the phone. I have tried that and it does not work for me.

• On my PC, my phone appears as a playback device ("Bluetooth Audo
  Renderer")
• On my PC, my phone does not appear as an input device / audio source.
• On my phone, my PC appears as a playback device ("Media Audio"
  connected), this similar to when I connect to an actual bluetooth
  speaker so I expect this to be correct.

What happens when I play music on my phone is that the internal speaker is indeed silent, as if it is playing to a bluetooth speaker. But the PC remains silent as well. I do not know how to verify in Windows that the bluetooth phone is used as an audio input device. It's not in the list of "recording devices" nor does the volume mixer show any bluetooth audio source. My phone does show up as a playback device as "Bluetooth Audo Renderer (Xperia Acro S)". But that's exactly the opposite of what I want (doesn't work either, but that's not the question here)

Are the three answers given to those other questions wrong? Am I doing something wrong? Or is something broken? I apreciate any help debugging this issue and I will gladly give any information needed.

Details:

1. Phone music -> 2. Android -> 3. bluetooth -> 4. Windows -> 5. PC Speakers

   1. Phone: Sony Xperia Acro S
   2. Android version: 4.04 (Cyanogenmod v9.1.0-hikari, kernel v3.0.8)
   3. Bluetooth: Cheap Chinese "Generic Bluetooth Radio" (USB, vendor id
      0A12, product ID 0001)
   4. Windows version: 8.1 Pro x64
   5. Speakers: 3.5mm jack output on-board on Asus P7H55-M (Realtek HD
      Audio)